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Showing results for tags 'P0304'.
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Hi, I'm trying to fix an issue with our 2003 Outback 2.5L Automatic 143K miles. Started with a regular CEL, then elevated to a Flashing CEL. Car would idle rough when it was damp outside and or cold. This is what I've done so far. When car was running well and it was dry outside I spritzed water, very lightly around the engine to re-create the problem. The very first place I hit caused the problem. I spritzed some water on the Coil Pack module, immediately a spark started jumping from Terminal 4 to the mounting bolt nearest the terminal. It was a very big spark and from my point of view it appeared like there was a crack in the terminal. I purchased a replacement and replaced the original with a brand new piece. The #4 terminal was blackened on the original coil pack. I did notice the connection from the spark plug wire on this terminal was looser than the others. I crimped it slightly with a terminal crimper and re-installed all of the wires. At first I thought I had it fixed, but not very long as the car sat idling the rough idle and the same spark happened from the same terminal to the mounting bolt. My first thought was to coat the mounting bolt and the end of the spark plug wire at Terminal 4 with Silicon RTV. This held up for a few days, but again, as soon as we had some rain, I had the same issue. I also ran the tank down to near empty and put in a bottle of quality, can't remember the name, Fuel System Cleaner, then filled the tank with 87 Octane Sunoco So went to Advanced Auto and per recommendations on the web I replaced the wires with a set of NGK, and a set of NGK replacement plugs. I went for NGK plugs that were for my car. The Autozone system came up with NGK G, which I found are Platinum tip. I've since read that I should have gone with copper. Is this a real issue? I used dielectric grease on all connections. I used Permatex Anti-Seize on the plugs. The number 4 plug looked like it had un-burnt fuel on it. The original plugs felt like they had been torqued too tight, but had no signs of stripping. It was just hard to break loose and I had to wrench them a long time until they were finger loose. Not having a torque wrench I put them in finger tight, then wrenched them 1/2-3/4 turn snug. I took the car on a quick local shakedown drive and it felt great, had more power than it had since we bought it. 2 days later we drove it much further, about 50 miles each way on the PA turnpike at speeds up to 75 MPH. No CEL's car felt great until... On the way home we were stopped by an accident. It was in the 20's outside. We sat idling for almost 30-45 minutes. As we were pulling away from there, the car started running a bit rough when de-celerating. Then about 10 minutes later as we sat in line to enter the turnpike the idle started getting rough and the CEL came on. My wife was afraid to drive it the remaining 35 miles home, but I said it's not flashing, and when we stopped it was OK if we put the car in neutral. When we got home I ran the car at idle in front of our home, about 30 degrees now. It was dark and I was looking for evidence of sparking again, but saw none. I've read through several threads on this issue on another Forum, before I found this one. They suggested after a tune up was performed that it's the Fuel injector if I'm lucky, or burnt valves if I'm not. Or possibly the small chance that the same plug or wire is bad again. I'm hoping that since it ran so strong for over 60 miles at speed and at idle that it's not the valves or head. I really pray that is true, because I don't have the money, or skills to repair that. So if you were me, where would you go from here? If the next step is the injector is a re-manufactured one OK? Which Brand? While i'm in there is it foolish to not replace both injectors on the drivers side of the block? I really would rather not buy 2. Everything seems to point to Cylinder #4. BTW, While I spent the last 20 years as a photographer, I went to school for electronics and feel comfortable around a DVM. Thank you in advance for any replies, I really appreciate any helpful feedback. Spiney-Dave- 7 replies
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- Cylinder 4 misfire
- P0304
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I have an automatic 2006 Legacy GT wagon with the turbo. It has about 185,000 miles on it. I just had a complete rebuild of the engine by Outfront Motorsports in Buena Park. They installed forged WRX pistons, ARP rod bolts and WRX engine mounts as upgrades for helping the engine last. They did a great job on the rebuild and are very helpful if I have any issues. My only concern is that I have piston slap in cylinders 2 and 4 but it doesn't effect the engine other than noise. Under hard acceleration, like merging onto the 91, my check engine light flashes and the transmission holds the gear up to redline. When I check the codes using my TORQUE app on my phone, I get P0304, and P0303, Powertrain cylinder misfire detected. Outfront can't seem to replicate it when they have the car. Also, sometimes the car is hard to start after I clear the code. What could be the cause and how to I remedy this issue? PS, The turbo has been rebuilt within the last two years; I use Rotella oil and change it at 4k miles. -
Hello there, My Outback started running a little rough, and the check engine light would periodically come on (which also made the cruise control not work, and the cruise light to flash). Sometimes I would be driving down the freeway with the cruise on, and I hit a small bump, which made the check engine light come on and the cruise to stop working. I took it to the auto parts store about a month ago, and there was only one misfire (I thought it was #3, but I could be mistaken. It recently got worse, so again, I took it to the auto parts store to do a code scan, it came up with P0301, P0302, and P0304 which is misfire in cylinders 1,2, and 4. It's probably worth mention that my Subaru is past due for it's 60K Service. I also just changed the plugs, with identical NGK's which made no difference whatsoever. I did some browsing, and it seems there are a few common culprits: Ignition wires, Coil, Timing belt? I am going to try running the engine in the dark to see if I can see any sparks on the ignition componets, once I get that knocked out, I will update. Any suggestions, or ideas will be recieved with much grattitude! Thanks! Edit: Sparks observed by the wire boot on the coil side. I am gonna go pick up some plug wires and dielectric grase, and see what happens.