… Continue reading "1999 Ford F150, P0306 Misfire Cylinder #6". Misfire is a common driveability problem that may or may not be easy to diagnose, depending on the cause. 5 ) for my daughter to drive to school. Hi, I am new to the forum and hope to learn much. The Subaru misfire can be related to the ignition coil. I also cleaned out the purge valve. P0301, P0302, P0303, P0304. Subaru flat 4 port and direct injection, non-turbo 2012: Cylinder misfire An intermittent issue of the engine warning light illuminating and fault code "P0302 Cylinder 2 misfire" detected. Subaru contends that this is all that is required to "repair" the leaks. The car would barely run so I replaced the plugs with oem ngks. When originally discovered in March, the curious thing about the misfires was that they were all in Bank 1. Code came back about 5 miles later as cyl 4 misfire (P0304). I first noticed that my car would shuttered only under heavy acceleration. 5L, and also soem 2000-06 Legacy and Outback vehicles. 2004 wrx 177,000 miles. We will certainly inform you regarding the Cylinder 1 Misfire Subaru Legacy image gallery we have on this website. P0305 Cylinder #5 Misfire. 2003 ford ranger - cylinder 4 misfire detected and misfire detected 1st 1000 rev Can anyone recommend the repair I need to make to a 2003 Ford Ranger pickup truck based on the codes I received when I plugged in my OBDII code reader. 5-L 4 Cyl) but check engine light permanently on for cylinder 4 misfire. So far I've replaced all the plugs, plug wires, new fuel filter, and new coil pack and injector in the number 4 cylinder. A misfiring cylinder in a four-cylinder engine is, pardon the pun, hard to miss. Ads by Google Car Trouble Subaru Forester Subaru Outback Car Diagnostics Subaru WRX Remove Advertisements Subaru Forester Owners Forum > Technical Forums and Vehicle Assistance > Problems, Maintenance, and Warranty Misfire on Cylinder No. Subaru said about 7,800 of its Legacy and Outback models were affected by a loose or out-of-position clamp on the fuel hose connecting the fuel filler pipe to the fuel tank. Here are the four different types of misfire and how to diagnose them: Ignition Misfire. Check engine light p codes are coded according to the system they belong to. 2L EJ22E 00-12 Subaru Outback EJ25: Valve Cover Gasket Sets - Amazon. If the engine speed fluctuates enough to cause the Crankshaft Position sensor signal to vary, the Engine Control Module can determine that a misfire is occurring. Look at the head gasket for a 7. Car keeps running - Subaru 2006 B9 Tribeca question. I have tried:. The obd2 code showed a misfire in the #4 cylinder (P0304 I think). My check engine light came on, so I took it to AutoZone to perform a check engine light test. One very important point to keep in mind about OBD II misfire detection is that the system does not tell you why the engine is misfiring. How much can a repair cause? It depends on the cause. Subaru is a Japanese car brand that makes coupes, sedans and SUVs. Of course, the battery's capacity helps smooth things out during periods of heavy load but wouldn't cause a misfire, at worst it would cau. ) fuel density, 3. Chrysler will reportedly extend warranty coverage for vehicles outfitted with 3. When the misfire monitor detects a misfire, it will trigger the check engine light with the specific cylinder number as the last digit in the P030X code. I also cleaned out the purge valve. the number after the 3 indicated the misfiring cylinder. Check the fuel pressure, a weak fuel pump can cause misfire codes to set on those subarus but still supply enough fuel to run the engine. Also, make sure you jot down the other codes, as misfire can be caused by a malfunctioning component or system. Will not pass the emissions tests. I had a buddy call me in a panic today, his 06 wrx limited failed a smog test on his way to sell the car because of misfire codes on all cylinders. 4) and senses misfires (engine knocking). This can set DTCs P0301 No. 2012 SUBARU LEGACY 2. Don't know if that means anything. Cylinder 4 Misfire Detected: Message Closed w/FIX. 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. Lack of power upon acceleration. The FSM has the valve clearance specs. That means that multiple cylinders misfire at random. Will do this a few times before cel stays on. After the top engine cover … Continue reading "2004 Ford Expedition, P0305 Misfire Cylinder #5". 5I CYLINDER 3,4,1 MISFIRE. most cases the #2 cyl misfire is timing belt related. What the P0304 code means. When replacing a head gasket, replace head bolts and properly torque the cylinder heads. From time to time I do hear the cam adjusters hitting the cylinder head covers but didn't want to think it could be the cause. 4l four banger. What Tests Can I Perform to Find the Cause of the Misfire Condition?. Or let me know what part do. · Engine Misfire Causes. 3 User Name User Name Remember Me? Password Log in. Basically, if the two oxygen sensor signals are the same, the converter is not working and will flag this P0420 catalyst code. Check engine light p codes are coded according to the system they belong to. P0301 Cylinder #1 Misfire. The engine tuning on my 4 cylinder 3RZ-FE 1996 Tacoma (190,000 miles) has been getting progressively worse over the past year. 005%, CO2 14. 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). Subaru misfire, Impreza, Forester, Outback, Legacy Fix Subaru misfires. It’s probably a missfre condition. A 6-cylinder engine features six pistons and produces a theoretical 50% more power than the same 4-cylinder engine. Also my current MPG is about 21 which is low in my opinion and from what I have seen other people get. If the engine speed fluctuates enough to cause the Crankshaft Position sensor signal to vary, the Engine Control Module can determine that a misfire is occurring. I was on the highway WOT into a 3rd and 4th pull when I noticed the CEL was flashing and then went away when I slowed down to cruise in 6th. Cylinder #4 Misfire Detected. CEL blinks at low rpm then goes out at around 3000. Check the condition of your spark plugs and spark plug wires. Ads by Google Car Trouble Subaru Forester Subaru Outback Car Diagnostics Subaru WRX Remove Advertisements Subaru Forester Owners Forum > Technical Forums and Vehicle Assistance > Problems, Maintenance, and Warranty Misfire on Cylinder No. Find a quality Subaru Legacy Cylinder Head and other used Auto parts from the top auto salvage yards. For instance cylinder 1 misfire is P0301, cylinder 2 is P0302 etc. What the P0304 code means. The P0304 Volkswagen code means that the cylinder 4 is misfiring or is randomly misfiring. Time to get to cylinder #5 coil. Check Engine Light Code P0304 Misfire Detection Monitor - Cylinder 4 Misfire Description: How does a P0304 code trigger the check engine light? This code will trigger the check engine light as follows: The misfire detection monitor, a software strategy built into the computer, is designed to detect an engine misfire. All six-cylinder Subaru 3. I then replaced the coil pack and the car ran fine for a couple of weeks. Of course, the battery's capacity helps smooth things out during periods of heavy load but wouldn't cause a misfire, at worst it would cau. Also Get Fuel pressure tested. It seems to be vey consistent. Now what? Misfire diagnosis in this kind of situation should be fairly easy. Subaru Forester Blinking Check Engine Light Rapidly it’s probably not a bad cylinder or valve issue. P0301 Cylinder 1 Misfire Detected Complete diagnosis with drive cycle B or C as well. It may not be Piston Slap worthy, but it’s got me confused. 4 earlier as well, and it would seem odd to me that 2 injectors would go at the same time. What could cause my car to misfire under load, like climbing a hill? Answered by: Carmen , An Expert in the Troubleshooting Category A misfire under load complaint can usually be broken down into 2 categories. Cylinder 4 Misfire Detected P0305: Cylinder 5 Misfire Detected Subaru Suzuki Toyota VW. Leave a for more videos! Here we go againCylinder 3 Ignition Coil has failed. either they need replaced or after market wires and non-NGK plugs were used. I've gone through TONS of threads on misfires with the 4. Re: Misfire and no check engine light? May 1st, 2012, 01:22 PM Any mis-fire in the cylinder will create a lean condition on the O2 sensor, rather the cause was lack of spark or plugged up injector. Welcome to the North American Subaru Impreza Owners Club: Tuesday August 20, 2019. CarMD reads your vehicles diagnostic. To learn more, see reviews below or submit your own. This seems to be the main symptom. The engine computer or PCM can detect a misfiring cylinder by monitoring the engine speed. Page 2- I need help! Spark plug broke off Mid Atlantic Impreza Club -- MAIC. The 2001 Jeep Cherokee has 4 problems reported for misfire. Internal Engine Defect. I have been having a misfire problem for 4 months that no one can seem to find out the engine spun a bearing and the entire long block was rebuilt at 102***mi. In some cases such as a cylinder misfire, it can be a bit more complex. While my scanner is only picking up a Cylinder 2 misfire right now, it was seeing cyl. 5 misfire 13 Answers. Have replaced coil packs and plugs. Independent Subaru shop. The power stroke is where the spark plug lights the air-fuel mixture inside the cylinder and you get a propagating flame front that evenly pushes the piston down. After a head gasket replacement. You have a code, you know which cylinder is misbehaving, and you can hear and feel the misfire. Got the CEL code read, and its coming up as p0303 and p0304, cylinders 3 and 4 misfires. V8 engines have a different tone than a 4-cylinder engine. Can a Bad Car Battery Cause Engine Misfire? When there is a problem with the ignition system of your car, it may result in an engine misfire. 55 Responses to Seattle Area Subaru Burnt Exhaust Valve. If you determine that the issue is a bad ignition coil, replace the coil. CarMD reads your vehicles diagnostic. to recap, about a month ago, I had a 1,2,3,4 misfire. If the misfire moved to cylinder number 4, then you have determined that the coil pack is faulty and needs. P0304 Subaru Cylinder 4 Misfire Detected: Code Meaning Engine-codes. You need to check the sparkplug wires with a meter and also that #3 wire is not leaking to ground. I then replaced the coil pack and the car ran fine for a couple of weeks. That combination tends to make me thing crank sensor related issue, istr it is a 2 wire inductive sensor it might be worth checking it out and the associated wiring. The engine computer or PCM can detect a misfiring cylinder by monitoring the engine speed. Had a CEL showing a misfire in cyl 4, so replaced all the injectors, swapped the coil packs between 2 and 4, and replaced the #4 sparkplug. Learn about this problem, why it occurs, and how to fix it. The Subaru misfire can be related to the ignition coil. This could cost $300-$400 for a 4-cylinder engine or $450-$700 for a V6. Fix Subaru misfires P0301, P0302, P0303, P0304 Subaru misfire problems can affect 1999-06 Subaru impreza, and Forester 2. Also, make sure you jot down the other codes, as misfire can be caused by a malfunctioning component or system. I had it hooked up and it read back cylinder 2 misfire. Yesterday the check engine light - Subaru 1999 Forester question. Almost definitely not. 2001 Subaru Outback 2. Subaru contends that this is all that is required to "repair" the leaks. P0301 Cylinder 1 Misfire Detected Complete diagnosis with drive cycle B or C as well. Some of these Subaru Forester problems can range from intermittent engine misfire issues or your Forester not starting. I often find that misfires are caused by ignition components so starting with the plugs and wires is a good start. The FSM has the valve clearance specs. I found only one related to engine misfire codes. I figured my injectors were getting plugged up since my car sits a lot. Average failure mileage is 84,800 miles. The P0304 code will be seen in cars where the ECU has detected that cylinder 4 is not firing properly. So I pulled off the wires and it seems that I am getting spark to that cylinder. P0300 Random Cylinder Misfire. I got a P0304 Cylinder 4 misfire but I can not reproduce it after swapping my ignition coils. If the misfire moved to cylinder number 4, then you have determined that the coil pack is faulty and needs. I had a buddy call me in a panic today, his 06 wrx limited failed a smog test on his way to sell the car because of misfire codes on all cylinders. It stands for: P0303: Misfire Detected → Cylinder 3 P0303 should not be ignored, and can be a threat to the drivability the Subaru Forester. ) fuel density, 3. Cylinder 9 Misfire Detected. 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. This is of course the ideal scenario. P0307 Cylinder #7 Misfire. I often find that misfires are caused by ignition components so starting with the plugs and wires is a good start. The code P0300 stands for random misfire. 2004 wrx 177,000 miles. What Causes an Engine Cylinder Misfire? Primary causes of engine cylinder misfires include loss of compression, an unbalanced air or fuel ratio, a loss of spark and a malfunctioning fuel injector. 4) and senses misfires (engine knocking). 5L, and also soem 2000-06 Legacy and Outback vehicles. A compression test is a good idea but a valve timing issue would almost definitely set misfire codes within a few minutes not a week. I recently bought a Subaru OutBack 2001 ( manual transmission 2. P0302 Cylinder 2 Misfire Detected Complete diagnosis with drive cycle B or C as well. I own a 2005 Subaru Impreza RS and the last couple days my check engine light is on and my cruise control is flashing. Cylinder 7 Misfire Detected. I put fuel injector cleaner through. No big deal except that the spark plugs, spark plug wires and coil assembly have already been changed with quality parts. Error Code P0303 is a common error code that indicates a misfire problem in the engine's cylinder, specifically cylinder #3. Average repair cost is $600 at 78,400 miles. Typically, fuel mileage will suffer as well. " I spoke with the last owner and he said the last time he replaced the sparkplugs was in feb the car is stock, nothing on it. Also, make sure you jot down the other codes, as misfire can be caused by a malfunctioning component or system. What does that mean? This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Now that you have read about the symptoms of an engine misfire, now you need to start looking for the problem. It was a hassle trying to find the exact replacement part but i eventually found it and swapped it out no problem. Ran fine before this by the way. Appearance has little to do with performance. Everything ran fine, except when hitting 70MPH or so in 5th gear, it will flick the CEL light on. P0304 Cylinder 4 Misfire Detected Complete diagnosis with drive cycle A or B as well. This page lists OBD-II generic powertrain trouble codes, a. 1 cylinder misfire detected, P0302 No. Cylinder 1 Misfire Detected. P0304 Cylinder #4 Misfire. How to Fix an Engine Misfire The best way to diagnose and repair a misfire problem is to use a CarMD. Anything below 100 PSI or below the norm or average reading is an indication of a failing cylinder. So I have an 02 Subaru WRX, I had the CEL come on, had the code read and it came up as Cylinder 2 Misfire. 2003 ford ranger - cylinder 4 misfire detected and misfire detected 1st 1000 rev Can anyone recommend the repair I need to make to a 2003 Ford Ranger pickup truck based on the codes I received when I plugged in my OBDII code reader. Check the condition of your spark plugs and spark plug wires. The Subaru misfire can be related to the ignition coil. the fact that its smoking in. This page lists OBD-II generic powertrain trouble codes, a. 3 User Name User Name Remember Me? Password Log in. 0-liter engines are split into two banks. Internal engine components are expensive and tend to be labor intensive to change. I keep getting a misfire on cylinder 2 and 4. 0 DOHC Turbo Cylinder Misfire Broken Valve Spring I had a 2002 Subaru Impreza WRX in the shop the other day that had me going for a bit. We have the largest selection of Subaru Legacy Cylinder Head parts at discount prices. Then the 3 and 4 misfire began. Finally I had a "fuel trim malfunction" code. Error Code P0303 is a common error code that indicates a misfire problem in the engine's cylinder, specifically cylinder #3. cylinder 4 misfire. MacFadyen on topic 2009 Subaru Legacy Cyl 3&4 Misfire @ 4,000 rpm Firing order is 1-3-2-4 so 3 & 4 are 360 crank degrees apart but on different banks. In this video i track down the misfire and have the car firing on all 4 cylinders by the end of the video. My engine idles rough and I'm experiancing some shaking in my shifter when in neutral. i had it a couple almost a year ago and it went away. subaru) submitted 4 years ago by stewart13 2016 DGM Impreza Sport 5MT I have an 01 Legacy GT and keep getting the check engine light for cylinder 4 misfire. 005%, CO2 14. Interestingly once I refitted the intercooler, she seems to idle better now and hasn’t thrown the cylinder 4 misfire code since. Page 2- I need help! Spark plug broke off Mid Atlantic Impreza Club -- MAIC. The other thing I noticed was that the misfire did not come in until the engine speed reached about 1500 RPMs. I'm not sure if the lean condition is still happening, of course, but it looks like Fuel Injectors are probably my biggest concerns. Refill the fuel so that the fuel meter indication is higher than the "Lower" level, and proceed to the next step. Ordered the remaining coils in order to have all 6 be new. Recently I've gotten a cel p0171 with the occasional misfire in cylinder 2 (ignition coil was replaced 3 months ago in this cylinder) when its under load. What could be the reason Engine Misfire #P0303 Please help - 2000 Subaru Forester. It had a misfire on cylinder one. 2003, 198k miles, overnight 1-6 cylinder misfire codes. Oxygen Sensor Heater Supported Complete EGR System Unsupported Results of On-board Oxygen Sensor Monitoring Tests O2 Test Parameter B1-S1 B1-S2 Unit. I've since replaced the knock sensor but when I went to clear the code there was a second code; P0304- Misfire Cylinder 4. Any engine that requires "bulletproofing" is a poor design - read pos. If you determine that the issue is a bad ignition coil, replace the coil. Ordered the remaining coils in order to have all 6 be new. Automotive Troubleshooting - Solving Car Problems. The power generated by an engine comes from the "power" stroke of the 4 stroke cycle. I have changed my spark plugs, the plugs wires looks okay to me so have not changed it yet. The obd2 code showed a misfire in the #4 cylinder (P0304 I think). Not each mode is necessarily supported by the engine ECU (ECM). The code P0302 means cylinder 2 misfires, P0303 is the cylinder 3 and so on. In this case we are left with a P0303 in the computer memory. Took to dealer for a leakdown test. 5L 4-cylinder Subaru, I was curious why the sound reminded me of old rear-engined Volkswagens, and seemed so distinct from inline 4-cylinder engines. Welcome to the North American Subaru Impreza Owners Club: Tuesday August 20, 2019. cylinder misfires are usually just plugs and wires. Engine DTC List Code Description. I keep getting a misfire on cylinder 2 and 4. To see how frequently Subaru Legacy problems occur, check out our car reliability stats. If the misfire moved to cylinder number 4, then you have determined that the coil pack is faulty and needs. International, Inc. How much does a cylinder misfire repair cost?. Take away any of those elements, and the cylinder will not produce the expected bang. Subaru misfire, Impreza, Forester, Outback, Legacy Fix Subaru misfires. So far I've replaced all the plugs, plug wires, new fuel filter, and new coil pack and injector in the number 4 cylinder. I did the compression test on cylinder 2 and I got 150psi and the same for cylinder 4. The Subaru CEL thread Service & Maintenance. 0-liter engines are split into two banks. P0304 Cylinder 4 Misfire Detected Complete diagnosis with drive cycle A or B as well. 3 cylinder misfire detected, P0304 No. The reasons for this belief revolve around the drivers side exhaust manifold. , offers the following information regarding a revised cylinder head bolt on 2010 midyear Subaru 2. Cylinder 7 Misfire Detected. The code came back as a number 4 cylinder misfire. The obd2 code showed a misfire in the #4 cylinder (P0304 I think). Fixing P0301 should be a high priority. I had one come in a while back that was setting cyl 2&4 misfires. to recap, about a month ago, I had a 1,2,3,4 misfire. I found only one related to engine misfire codes. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 4. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 2. I had it hooked up and it read back cylinder 2 misfire. FreeAutoMechanic. It is probably the coil on cylinder number 4. The FSM has the valve clearance specs. Codes are PO300 & 301 which when I read them says I have a misfire in all four cylinders. Causing this ticking or misfire condition may be the result of an AFM lifter. Cylinder 4 Misfire Detected P0305: Cylinder 5 Misfire Detected Subaru Suzuki Toyota VW. P0304 Subaru Description When a misfire occurs, engine speed will fluctuate. Timing belt and water pump been replaced at 93k miles $2800 for the entire car. The Subaru Mechanic I'm going to connect you with knows all the tricks and shortcuts. Possible causes of OBD code P0304 Hyundai A code P0304 Hyundai 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. The code is showing a "misfire" (chamber 4) iCode 304 I believe, in the ignition system but no other info is available. The car also loses power occasionally at high speeds (in 5th gear on highway), which seems logical given the misfire codes. I drive the car for another 150 miles with no further performance issues. The inadequacy or absence of any of these elements will cause an engine misfire. Freeze data during a scan should show you the 1st code that set. The Subaru CEL thread Service & Maintenance. It was bad. 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 has always seemed to run perfectly. You have a code, you know which cylinder is misbehaving, and you can hear and feel the misfire. So I pulled off the wires and it seems that I am getting spark to that cylinder. Fixing P0301 should be a high priority. Measure the cylinder compression of ALL the cylinders. Average failure mileage is 84,800 miles. P0304 is a diagnostic trouble code seen when a misfire is detected in cylinder 4. Nissan 4 cylinder engine. Today on my way to work, my check. 5L, and also soem 2000-06 Legacy and Outback vehicles. The affected vehicles were produced between June 3, 2003, and Aug. If the misfire moved to cylinder number 4, then you have determined that the coil pack is faulty and needs. Have replaced coil packs and plugs. Also my current MPG is about 21 which is low in my opinion and from what I have seen other people get. It idles rough when warm(not - Answered by a verified Auto Mechanic. I went to the mech shop to pick up my veh after hours as shop had already. Original code was a injector cyl#1 open. The other thing I noticed was that the misfire did not come in until the engine speed reached about 1500 RPMs. Error Code P0303 is a common error code that indicates a misfire problem in the engine's cylinder, specifically cylinder #3. Symptom: Check Engine Light Illuminated and engine misfire, may also detect loss of power or hesitation while accelerating. The mechanics at the local Subaru dealership seem to be baffled. For a cylinder misfire problem, you need to change components, such as coils, spark plugs, etc. Cylinder 2 Misfire Detected. A compression test is a good idea but a valve timing issue would almost definitely set misfire codes within a few minutes not a week. The Subaru Mechanic I'm going to connect you with knows all the tricks and shortcuts. I did get a cylinder 1 misfire also but after clearing them I drove for a bit and the cylinder 4 misfire code came back. This could cost $300-$400 for a 4-cylinder engine or $450-$700 for a V6. The engine idles a little rough and the cel is on. Look for pass or fail for each cylinder, the scan tool data for mode 6 showing a misfire for cylinder #4 may look something like this; TID $53 CID $01 Pass (Cylinder #1) TID $53 CID $02 Pass (Cylinder #2). P0300 is a code generated by the Powertrain Control Module or Engine Control Module basically telling you that it has detected a random cylinder misfire. ) compression and 4. I did make the mistake of not compression the tensioner piston back in when I had the head off the get resurfaced. How many head bolts per cylinder and how many of them are shared? Every time a cylinder fires you could say a stick of dynamite goes off in it. the number after the 3 indicated the misfiring cylinder. Buy LIMICAR Cylinder Valve Cover Gaskets With Spark Plug Tube Seals and Grommets for 98-01 Subaru Impreza 2. Wires look great (OEM Subaru) and I believe they were changed at 60k but just to double check, I swapped the cylinder 4 wire with cyl. Something else to look at in the spark burn line is the amount of "hash" it contains. Now if you are getting P0304, that means that the problem moved to cylinder 4, so the ignition coil is the problem. All six-cylinder Subaru 3. either they need replaced or after market wires and non-NGK plugs were used. Head bolts do stretch ever so slightly so the cylinder head lifts off the block. I was on the highway WOT into a 3rd and 4th pull when I noticed the CEL was flashing and then went away when I slowed down to cruise in 6th. P0302 Cylinder 2 Misfire Detected Complete diagnosis with drive cycle B or C as well. This time cyl 4 codes are being read from my plx kiwi that i keep in my car. Hey guys i own a 1997 impreza which seems to misfire/backfire(not sure what 1) it seems to jump back and forth and lose some power when i put my foot down, ive checked and changed wires and spark plugs,a friend told me to replace the coil pack to solve the problem. Wires look great (OEM Subaru) and I believe they were changed at 60k but just to double check, I swapped the cylinder 4 wire with cyl. The other thing I noticed was that the misfire did not come in until the engine speed reached about 1500 RPMs. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 2. Possible causes of OBD code P0304 Subaru A code P0304 Subaru 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. 3 cylinder misfire detected, P0304 No. It's probably a missfre condition. As mentioned, a cylinder misfire can happen due to a few reasons, and to make things simple, we created a table to show you exactly what repairs may be required to fix the misfire condition. i have now got it 3 times in the last week. You are here: Check Engine Light Home > Check Engine Light Codes (Generic Powertrain) Check Engine Light Codes. Engine Stalls, Misfire Code, & Cylinder Misfire The engine may be stalling because it isn't getting enough throttle opening. This time the check engine light and cruise both blink, and after about 5-10 blinks the check engine light stays on. Going up a steep hill. Smell of unburned gas exiting the tail pipe. Subaru Forester P0304 Definition.