What Causes A Cylinder 4 Misfire

The largest 4Runner community in the world. 4 - Misfire. No check engine light or traction lights but put the scanner back on and it read the p0300 random misfire but no check engine light or rough idling. Truck sat since december periodically ran, (i'm buying the truck but now it has a misfire) 4. It will usually run alright for a few minutes then starts acting up after a little while. I checked the plugs and they are Bosch Platinum 4's. So I am suspecting a burned valve on cylinder 7. car has 200k on it with original plugs and wires. Ignition system fault-spark plug(s), ignition wires, coil 2. Possible causes of OBD code P0304 Mini A code P0304 Mini may mean that one or more of the following has happened: Faulty spark plug or wire Faulty coil (pack) Faulty oxygen sensor(s) Faulty fuel injector Burned exhaust valve Faulty catalytic converter(s) Running out of fuel Poor compression Defective computer. >"Also a lot of misfire is noticed at cruising speed on the highway while running at 60- 65 mph. I took it in to the local auto part store they said Cylinder 4 Misfire. Freeze data during a scan should show you the 1st code that set. If the problem persists more tests needs to be done to diagnose problem, see "Possible Causes". The nice thing about P0304 is that it's a cylinder specific trouble code, which makes diagnosing the problems simpler than P0300 , which means that the cylinders are randomly misfiring. 8T with engine misfirepossible causes 2006 Passat, 59000 miles, ever since 40000 mile service have had very rough idle w/Cy 1-4 misfires & 10 different codes indicating a mass air flow problem, took in to dealer, had crank case breather valve replaced ($265. In the case that misfire cannot be reproduced, the reason may be because of the driving with lack of fuel, the use of improper fuel, a stain of the ignition plug, and etc. It has a coil pack (well the pre 2000 ones do I believe) and each coil does 2 cylinders and fires with different polarity or something so the spark is higher in whichever cylinder it wants although it reverse sparks in the other cylinder (this is why you have to use DUAL platnium or iridium/platnium plugs becuase it eats them up). 00) still with terribly rough idle but light has not come back on in. The ECM counts the number of times the engine speed change rate indicates that misfire has occurred. One of the most common causes of an engine misfire condition is the tune up parts. The ECM detects a misfire in the following ways: 1 st time-Misfire occurs which may damage TWC (three way catalyst) MI starts blinking. Cylinder compression OK. - Duration: 44:07. replaced spark plugs, wires and coil pack and still the same problem in addition cylinder 1 misfire as well as 2 and 3. 46 for parts and $91. Cylinder Misfire Codes 2007 Toyota Avalon Trouble shooting a misfire, Code P0300, P0301, P0302, P0303, P0304 1280 x 854 · 92 kB · jpeg Source 2000 Chevy Blazer 4. What would cause this? This is a 1998 Windstar. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 4. The P0304 Mini code means that the cylinder 4 is misfiring or is randomly misfiring. P0304: Misfire Detected → Cylinder 4 P0304 is certainly a cause for concern, and should be considered a threat to the drivability your 200. A failed ignition coil or a bad spark plug wires. Loss of Engine Spark. If I remember right there was a lean code too. I had replaced my spark plugs and plug wires not to long ago and the engine started to miss the other day. Is this the next step that I should take? Edit: Originally had a check engine light and rough idle but new plugs and coil fixed that. Possible Causes INTERMITTENT DTC. Modular V8 (4. I would think two cylinders would drop out if a primary coil went bad. Truck sat since december periodically ran, (i'm buying the truck but now it has a misfire) 4. A misfire alone doesn’t necessarily mean that a rocker arm has suddenly fell out of place. so far so good. If the problem persist more tests needs to be done to diagnose problem, see "Possible Causes". See here for a step-by-step guide on how to diagnose and fix check engine light code P0305. this time the codes that came back were m. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 4. Fix a cylinder misfire by determining where it is occurring, diagnosing the problem and replacing defective parts. 9 in it that my daughter drives also kept throwing a 4 cylinder missfire CEL code. The only thing is that the threads seem to have been left unanswered. What cause engine misfire? An engine depends on three things to fire the cylinder – an adequate amount of fuel, oxygen to burn the fuel, and a spark for ignition. 1, cleared the fault memory of ECM restarted the car but still cylinder 4 misfires. I pulled out plug #2 and it has oil on the tip, not a lot, but enough to cause it to misfire. Loss of spark is also a prime suspect in engine misfire. HC 12PPM, CO 0. it would burn the coolant cause a misfire the warm up and seal the headgasket again. Read also: The average cylinder head crack repair cost. Best Answer: Diesels dont as a rule misfire. However, the most common cause of an ignition misfire is a bad ignition coil. The 2006 Acura MDX has 1 problems reported for cylinder #4 misfire and cracked head. Cylinder compression OK. The symptoms of a misfire will be recognizable to the driver because their engine will feel like its stumbling for a few seconds and then regain its pace again. 3 with AFM that was NOT caused by a stuck value, collapsed lifter, bad lifter solenoid or flat spots on the #4 cam lobes? I have an obvious misfire at idle which makes the engine stumble about every two seconds and I notice a slight RPM fluctuation on the tach. FIXD explains symptoms, causes, and severity of code P0305. I had intermittent misfires that started with operating in low temps then stopped after running awhile. A good friend phoned me from King of the Hammers last year, sharing that his late (2004) TJ Wrangler 4. The fuel control will shut the fuel injector off to a cylinder if a misfire code is detected to keep raw fuel from dumping into the catalytic converter. 4% at idle with the live data list recording 20 misfire counts on number 2 cylinder! One point to note here was the misfire count fell to zero on number 2 cylinder as soon as the engine speed was increased just 150rpm above idle (return to idle, the misfire count began to increase again). It would run like crap (obvious misfire) and running it hard would clear it until it was babied again for too long of a time. cylinder 4 misfire 5 Answers. With and Without Misfire Codes. Hopefully this isn’t an issue because changing injectors is a pretty involved task. New cap and rotor,swapped wires with another cylinder still nothing, Checked compression 150lbs, new spark plug and i got zapped a few times playin with it. A failed ignition coil or a bad spark plug wires. The blinking would stop after a few minutes and the light would go away. I have changed the plugs and Swapped that coil / wire but still get a misfire. Causes the number 4 cylinder to misfire on a 2002 ford escort se - Answered by a verified Ford Mechanic We use cookies to give you the best possible experience on our website. The ECU can’t always tell you what specific part is broken, but in the case of our truck, it had stored data indicating there was an engine misfire in Cylinder #4. Having a a major dilema with a rough idle / Multiple Cylinder Misfire on my 2001 Chevy S10. (the number is divided by two because its a 4 stroke and any given cylinder only fires every once per two rotations of the crank) Total time of spark over 1 hour = sparks/hour*spark duration (in hours) =. Imbalanced Air/Fuel Mixture. Found MDS solenoid #2 for cylinder 4 and wiring harness melted to top of the engine block. A misfire should be diagnosed from the simplest and most likely to the more complex. this time the codes that came back were m. Code indicated #4 misfire. The misfire codes have increased again to up to 4 different cylinders. I replaced the plugs a while back with the NGK's from the auto parts store that weren't the $15 ones, but the $3 ones. 3L with 100K miles on it. The check engine light came on a few months back. 04 Ford Ranger Cylinder 4 Misfire causes? For a while now my 2004 Ford Ranger has been getting a check engine lights periodically indicating a Cylinder 4 Misfire. car has 200k on it with original plugs and wires. Some engine control modules are using the resistance of the ignition coil, and when an ignition does not occur, the engine control unit measure it through the wirings, and it would result in a DTC code. The misfire occurs as a result of a partial combustion process occurring inside one of the cylinders. if it misfires in cyl. Cylinder 4 misfire appears to be a common problem on the Triton V8 especially on trucks. More common causes of a misfire could be a bad coil, worn plug or plugged injector. The first thing to understand in this instance is that no. I hope it doesn't sound like I'm squeezing a bunch of problems into one message, because I'm trying to find it if these problems could be related at all. Originally Answered: What causes a #4 cylinder misfire? The probability is that the fault is electrical rather than mechanical. That means that multiple cylinders misfire at random. But I have seen 1 bad misfire only affect 1 other cylinder. they put all new heads and components on and got it back today. And when the misfire rate equals or exceeds the count indicating that the engine condition has deteriorated, the MIL lights up. Will not pass the emissions tests. My 08 SE plus w/ the 3. the rpm drop then pick back up (the rpm gauge is fluctuating. Symptoms of a Misfire. The fuel control will shut the fuel injector off to a cylinder if a misfire code is detected to keep raw fuel from dumping into the catalytic converter. I couldn't check the ones in the back of the engine. 04 Ford Ranger Cylinder 4 Misfire causes? For a while now my 2004 Ford Ranger has been getting a check engine lights periodically indicating a Cylinder 4 Misfire. Cylinder 3 misfire is only code that ever trips or shows up, no other codes or info appears when scanned for problems. Loss of Engine Spark. It would make sense that since cylinder No. Like if you are under heavy load and it miss fires then you have a bad plug wire. It was bad enough to get the CEL flashing. Checked the compression in the #2 and 4 cylinders and checked the pcv and air filterall are good. Have swapped iginition coils and have the same problem on cylinder four meaning that cylinder 4,ignition coil is good. Read also: The average cylinder head crack repair cost. See here for a step-by-step guide on how to diagnose and fix check engine light code P0304. 0 liter never had any major issues with it in the past 8 years I've owned the jeep. The term 'tune up' usually means changing the spark plugs, igni. Ive posted about this situation before but it still going on. this time the codes that came back were m. Freeze data during a scan should show you the 1st code that set. the question about valve lash adjustment is a valid one; I would also inspect the spark plug on that cylinder and swap the coil with another cylinder to see if the misfire code follows it. The first sign of the problem was the service engine light would blink intermittently when driving on the highway or revving the gas. No misfires at other times or on WOT. A lot of problems can cause a misfire code. Next, the scan tool will be used to monitor the misfire counter for cylinder 4. car has 200k on it with original plugs and wires. Exhaust pressure at tailpipe pulses. It ran great for many years. and it loses power and it starts shaking. cylinder 4 misfire 5 Answers. let you know if this still ok after a couple weeks!. We changed them at home. when the vehicle would cool down the coolant would just get by the headgasket and have a little coolant in the cyl when the vehicle would start again. In order of most likely culprits: - Bad coil ( if COP) equipped ( One coil per individual cylinder) -Bad HT wire -Bad HT wire boot, causing "tracing" on the porcelain of the plug -related to the. The A2 is certainly not dull. Faulty spark plug 4. P0308 Cylinder #8 Misfire. Any advantage in having changed the spark plugs for platinum ones? The mechanic who suggested and changed the spark plugs seemed convinced that this was worthed. MY access port displayed "P301 Cylinder 1 misfire detected", "PFFF", "PFFE". **FIXED**Cylinder #4 misfire,Code-P0304 ***I FIXED IT*** 4/18/04 Ok, Before everyone ask if I did a search, I did. Plugs then coils are THE two most likely causes, followed at a great distance by poor fuel atomization by the injectors. The poppet injectors in the spider assembly's do go bad, but they usually cause multiple cylinder misfires rather than a single cylinder, and they usually leak fuel into the cylinder after a shut down, which will make them smell rich on start up and may idle rough after a re start (which will usually set a P0172 or P0175 code also). As noted here, there are a number of reasons that cause a cylinder to misfire. May need to open wiring bundle to check individual wires. The "soft" misfire, often called a surge, is commonly associated with fuel related issues. 4 spark plug to cyl. spark plugs in cylinder numbers 1,2,3, and 4 (5 and 6 were tough to get to) and they had a little bit of. i have changed 40 dollar set plugs gapped at. >"Also a lot of misfire is noticed at cruising speed on the highway while running at 60- 65 mph. It sometimes stutters while on the road getting occasional misfire which eventually leads to, what I'm guessing is, the cylinder 4 completely turning off (ECU?). , move cylinder 7 plug to say cylinder 3 and if the misfire is now P0303 then the plugs are at fault. Too much air, too much gas, stuck valve, timing. Hi all, I have a Jeep Grand Cherokee 4. If the misfire rate does NOT reduce to less than 5 per minute after. Are there any sensors that will cause just a single cylinder to misfire?. There are a variety of different misfire causes that can occur that can keep a cylinder from combusting properly. Faulty ignition coil 4. 2011 GMC K1500 4x4 Crew-Cab Pickup Truck, 8-cyl Auto, A/C, (153,962 miles) (starts and runs, cylinder #6 misfire / no compression, stability a light on, service traction control light on, low oil pressure,) NOTE: This unit is being sold AS IS/WHERE IS via Timed Auction and is located in South Beloit, IL. Additionally the serial diagnostic code indicated: "significant misfire cylinder 4". The misfiring cylinder is causing the "no activity" dtc related to the 02 sensor as when a cylinder misfires,there is alot of oxygen in the exhuast because the fuel did not burn. If the problem persist more tests needs to be done to diagnose problem, see "Possible Causes". So I turned on the car again and no misfire car was running normal, I decided to take it around the block. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 4. I have changed the plugs and Swapped that coil / wire but still get a misfire. 0L is becoming more common and getting harder to diagnose. What does that mean? This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. put plugs and wires in and cleared codes. A condition known as "lean misfire" can occur if there is not enough fuel. Sometimes it is lumpy on startup for a few seconds too. It depends on the cause. For a Ford motor R1= cylinder #1, R2=cylinder #2, R3=cylinder #3, R4=cylinder #4, L1=cylinder #5, L2=cylinder #6, L3=cylinder #7, and L4=cylinder #8. I'm not sure how I could have burned a valve. I am thinking that it might be a faulty injector. Check the coil, the wiring and also check cam shaft sensor and crank shaft sensor. I've had the wires, coils, plugs, replaced and the fuel injectors cleaned. If your engine has a high-tension distributor, the fault can be anywhere between the #4 connector on the distributor cap, through the HT lead to the spark plug. 3 with AFM that was NOT caused by a stuck value, collapsed lifter, bad lifter solenoid or flat spots on the #4 cam lobes? I have an obvious misfire at idle which makes the engine stumble about every two seconds and I notice a slight RPM fluctuation on the tach. My cylinder misfire code is on #5. If the problem persists more tests needs to be done to diagnose problem, see "Possible Causes". 1, cleared the fault memory of ECM restarted the car but still cylinder 4 misfires. P0304 cylinder 4 misfire and according to the local dealership that is synonymous with this defect, keep in mind the car has only 27k miles, Trouble codes related to this would tell you a possible coil, spark plug, evap leak or egr valve, the dealer confirmed it was neither one and it was the faulty cylinder head. What are all the possible causes of a misfire minus a fowled plug? Can it be serious?. The damage you see will help you determine the cause of the misfire. 1999 f-150 5. NGK Technical Training 85,707 views. Ive posted about this situation before but it still going on. cuz i couldn't reach. The result is in ability to maintain the correct air to fuel mixture within the engine and a misfire occurs. For example, if the misfire is caused by a bad on-plug ignition coil, which is quite common on many newer cars, the repair might involve replacing a bad coil and all the spark plugs. Car started immediately. I have have been dealing with this P0171 diagnostic trouble code for many years on many different year make and model vehicles. PO 304 Cylinder 4 Misfire Was going to replace the sparkplug, but which is cylinder 4?! And any other suggestions for this CEL? update: bought new Iridium sparkplugs (same as old ones). Each of these withanber of causes. Its not one or two reasons. New cap and rotor,swapped wires with another cylinder still nothing, Checked compression 150lbs, new spark plug and i got zapped a few times playin with it. The spark plugs, ignition leads, Speedo Sensor, idle control valve, accelerator sensor, fuel rail with for injectors and catalytic converter has. Lean misfire causes that only affect one cylinder include a dirty fuel injector, an open or shorted fuel injector, or a problem in the fuel injector driver circuit (wiring or PCM). Holding the revs slightly on stopping will stop this from happening. This condition only affects one cylinder including a shorted or open injector, dirty cylinder and fuel injector poor wiring. high or low fuel pressure. Fuel injector issues will cause a cylinder specific misfire. Fabia MK2 misfire on cylinder 4. This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Also, make sure you jot down the other codes, as misfire can be caused by a malfunctioning component or system. I finally broke down and paid Ford the $125 to hook it up to their computer to identify what the problem was. Loss of Power Accompanied by Abnormal Vibrations. The complaint was a bad misfire on cylinder #2 with some other random misses on the other cylinders. So checked the spark plug,it was terrible. The other day my '97 V6 T100 started showing symptoms of a cylinder misfire. Jump to Latest Follow 1 - 5 of 5 Posts NOTE: Anything that affects the speed of the crankshaft can cause a misfire DTC. FIXD explains symptoms, causes, and severity of code P0304. If the problem persist more tests needs to be done to diagnose problem, see “Possible Causes”. This is not what causes it to run bad when cold, but a separate problem. Cylinder 1 misfire. If your cars sound is extraordinary strange, it's most likely misfires that you could hear. An engine miss due to bad spark plug wires can also cause this to happen on heavy loads where you mash hard on the gas pedal, and you usually can hear a popping or sputtering noise under the hood. Defective New Crank Sensor Produces Tiny Signal Glitch and Causes Misfires. There are a variety of different misfire causes that can occur that can keep a cylinder from combusting properly. Misfire history showed misfires scattered on all cylinders with the majority on cylinder 3 and the next large chunk on cylinder 4. only happens at idle and rarely 2 cylinders counting at the same time. 4 cylinder is actually no. I show you how to test injectors, compression. Started driving to work and all of a sudden I noticed a misfire at idle, or low RPM/low load. A garage and the Ford dealer cannot detrmine cause. also when i get low to about quarter tank of gas and pull into gas station to fill up. Holding the revs slightly on stopping will stop this from happening. Symptoms Symptoms may include: the engine may be harder to start; the engine may stumble / stumble, and/or hesitate; other symptoms may also be present; Causes. Another cause of misfiring is a weak fuel injector a condition that is referred to as "lean misfire" and occurs because there is no enough fuel in the combustion chamber. How to Fix a Misfire Easy step by step guide on how to troubleshoot and repair an automotive engine cylinder misfire P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 and P0308, though appearances may vary, the process is similar for most vehicles. Defective New Crank Sensor Produces Tiny Signal Glitch and Causes Misfires. A code reader, available from parts stores, will permit you to jack into the engine-control unit (ECU) and get a dialog of what’s up, what’s wrong and where it’s happening. Plugs then coils are THE two most likely causes, followed at a great distance by poor fuel atomization by the injectors. 0L Rubicon engine would not idle on a hot restart. Having a a major dilema with a rough idle / Multiple Cylinder Misfire on my 2001 Chevy S10. vehicle still had a misfire. MY access port displayed "P301 Cylinder 1 misfire detected", "PFFF", "PFFE". A cylinder misfire can happen for various reasons, and when it happens, it generally causes the car to run rough, jerk or buck. 3L Vortec engine. Updating the ROM in the ECU to the latest revision from Subaru helps alleviate most false misfire issues. 0 V-8 engine. A misfiring cylinder in a four-cylinder engine is, pardon the pun, hard to miss. ) up-down-up down every 3 or 4 power strokes. I read it and it was a P0300 Random/Multiple Misfire. Found MDS solenoid #2 for cylinder 4 and wiring harness melted to top of the engine block. Code P0304 (Misfire Cylinder 4) reading on my 2001 Outback with the check engine light on. There is always something :p. A misfiring cylinder in a four-cylinder engine is, pardon the pun, hard to miss. There are a variety of different misfire causes that can occur that can keep a cylinder from combusting properly. I took it in to the local auto part store they said Cylinder 4 Misfire. not using oil. If your engine has a high-tension distributor, the fault can be anywhere between the #4 connector on the distributor cap, through the HT lead to the spark plug. That means the power-producing explosion, in the cylinder does not take place. For example, let's say that cylinder number 2 is misfiring and you suspect a bad spark plug, spark plug wire, or COP coil. I received 2 codes, P0304 - Cylinder 4 Misfire detected and P0316 - Misfire detected 1st 1000 revs. P0304: Misfire Detected → Cylinder 4 P0304 is certainly a cause for concern, and should be considered a threat to the drivability your 200. Lean misfire causes that only affect one cylinder include a dirty fuel injector, an open or shorted fuel injector, or a problem in the fuel injector driver circuit (wiring or PCM). ) fuel density, 3. This is because the firing order of this. The misfire codes have increased again to up to 4 different cylinders. 44% and O2 0. car has 200k on it with original plugs and wires. I checked the problem and it was a P0305, cylinder 5 misfire. I also replaced the air filter which was really dirty and put injection cleaner in the fuel. I've got a 115K miles on it, the timing belt has never been replaced, plugs were recently changed (the light came on before the plug change). Misfire history showed misfires scattered on all cylinders with the majority on cylinder 3 and the next large chunk on cylinder 4. The loss of 25% of the engine's power output is the equivalent of a horse trying to run on three legs. I couldn't check the ones in the back of the engine. Replaced the plug,reset the computer and runs great. I've had the wires, coils, plugs, replaced and the fuel injectors cleaned. Possible causes. Troubleshooting Misfires on Ecoboost Vehicles. 60v, ECT sensor over 176°F, VSS under 3 mph, then test started and PCM detected a misfire in 15% of the engine cycles in 200 revolutions, or detected a misfire in 2% of engine cycles in 1000 revolutions. 7 P0300 Multiple Cylinder Misfire. car has 200k on it with original plugs and wires. NGK Technical Training 85,707 views. P0304: Misfire Detected → Cylinder 4 P0304 is certainly a cause for concern, and should be considered a threat to the drivability your 200. 6L (8th 500 x 500 · 37 kB · jpeg Source. If your engine has a high-tension distributor, the fault can be anywhere between the #4 connector on the distributor cap, through the HT lead to the spark plug. this time the codes that came back were m. In most cases, a cylinder misfire is caused either due to old spark plugs that need to be replaced. changed wires 3 times. i take the gas cap off this car sounds like a popcorn machine when the. I've changed the spark plugs, spark plug wires, and fuel injectors but the engine light still pops up; sometimes flashing. Its not one or two reasons. If the problem persist more tests needs to be done to diagnose problem, see "Possible Causes". I was stumped. A cylinder Misfire cause by direct fire ignition coil system. See articles P0300 & P0301 for in depth troubleshooting of the four misfire causes: fuel, spark, timing. Leaky intake. 7 P0300 Multiple Cylinder Misfire. Re: Random Misfire, and cylinders 2,4,6 misfire. Sometimes the engine control unit cannot detect which cylinder the misfire occurs on and it will put the DTC code P0300 (random misfire). I couldn't check the ones in the back of the engine. PREPARATION: (a) Disconnect the ignition coil. i went to dodge and made them do a diagnose and they said its something in side the cylinder and will coast me 1700+ to fix. Possible causes of OBD code P0304 Mini A code P0304 Mini may mean that one or more of the following has happened: Faulty spark plug or wire Faulty coil (pack) Faulty oxygen sensor(s) Faulty fuel injector Burned exhaust valve Faulty catalytic converter(s) Running out of fuel Poor compression Defective computer. This is because raw fuel will kill the cat and or cause it to overheat. What cause engine misfire? An engine depends on three things to fire the cylinder - an adequate amount of fuel, oxygen to burn the fuel, and a spark for ignition. Sometimes it takes a combination of issues in order to make a cylinder misfire. injector fault 4. Lean misfire causes that only affect one cylinder include a dirty fuel injector, an open or shorted fuel injector, or a problem in the fuel injector driver circuit (wiring or PCM). If the misfire is happening randomly it may cause a check engine light to stay on and display the code P0300. NGK Technical Training 85,707 views. HC 12PPM, CO 0. Followers 2. Primary or secondary ignition components can go bad and prevent the spark from being delivered properly to the cylinder which would result in an engine or cylinder misfire. 4 coil with new coil and moved cyl. Now its just small amounts of misfires per cycle. 7 P0300 Multiple Cylinder Misfire. Too much air, too much gas, stuck valve, timing. They can cause misfires. 7 liter tundra with 208,xxx miles. In most cases, that would be an accurate conclusion, but having higher compression will rarely cause a cylinder to misfire. swapped injectors. And when the misfire rate equals or exceeds the count indicating that the engine condition has deteriorated, the MIL lights up. I replaced all the plugs with NFL and also s new coil pack for cylinder 6 and after 3 or 4 days it will reappear. For example, if the misfire is caused by a bad on-plug ignition coil, which is quite common on many newer cars, the repair might involve replacing a bad coil and all the spark plugs. The nice thing about P0304 is that it’s a cylinder specific trouble code, which makes diagnosing the problems simpler than P0300 , which means that the cylinders are randomly misfiring. If switching components to a good cylinder doesn't eliminate the original misfire then there could be a problem with compression. I have have been dealing with this P0171 diagnostic trouble code for many years on many different year make and model vehicles. Take it back to the shop and they call me back and tell me now they have to replace the gaskets on Bank 1 cylinders 1 & 3 cost to fix those $425. It will suck paper back towards the exhaust during. I bought this truck about a month ago, and this problem only started happening after this work was done. Ran diagnostics and found codes P0304 P1414 for cyl 4 misfire and cyl 4 reactivation control performance. " If it still misfires under acceleration or at higher speed with richer mixture, then it has to be a spark problem. I have two codes that say that I have a:-P0316 Misfire Detected 1st at 1000RPMs-P0303 Misifire Detected in cylinder 3 What does this mean? Spark plugs are relatively new (only like 15-20000 miles), timing is at 10 degrees, I have not opened the hood in like 1 month and I have not floored it for about 2 weeks. Misfire at idle, the engine will shake , when driving you hear the misfire ,the non steady beat of 4 cylinder firing, is no longer perfect succession. vehicle still had a misfire. Hooked up a vac gauge to the brake booster line off the intake manifold and the needle stays in the middle of the green "good engine" range on the gauge at idle. Three good trips to turn off the MIL. QUICK INJECTOR MISFIRE CHECK. Its a V6 4. For a cylinder misfire problem, you need to change components, such as coils, spark plugs, etc. As we know, the general causes of a misfire fall under the ­general headings of 1. We changed them at home. 0 V6 misfire Not to scare you but I chased this same problem around for a while, changed plugs and wires and coil pack and kept getting either cylinder 4 or 6 misfire code. I bought it a few months back and haven't had any problems with it until now. If it were a fuel problem, wouldn't that cause all the cylinders to intermittently misfire, not just cylinder one? Thanks in advance for any info or advice. Here is How to fix a Misfire on a gasoline engine. I checked the plugs and they are Bosch Platinum 4's. Causes of random cylinder misfire (code P0300) include: - Bad mass airflow sensor. Plugs then coils are THE two most likely causes, followed at a great distance by poor fuel atomization by the injectors. New cap and rotor,swapped wires with another cylinder still nothing, Checked compression 150lbs, new spark plug and i got zapped a few times playin with it. For example, if the misfire is caused by a bad on-plug ignition coil, which is quite common on many newer cars, the repair might involve replacing a bad coil and all the spark plugs. Also read that there is another fix for this I think it is new valve ring retainers but don't quote me. The misfire occurs as a result of a partial combustion process occurring inside one of the cylinders. 6L (8th 500 x 500 · 37 kB · jpeg Source. If the problem persist more tests needs to be done to diagnose problem, see "Possible Causes". If the problem persists more tests needs to be done to diagnose problem, see "Possible Causes". If P0302, P0304 or P0306 that would be on bank 2, so remove the valve cover and measure the camlobe lift to make sure the camlobes on that cylinder are not wiped or flattened down. 2005 Ford F150 King Ranch Edition 5.