Did you gap your plugs correctly and according to the Service manual?Hi guys,
I'm Hoping at least some of you still keep up with this thread. I have an 05 STI (COBB AP, COBB SF Intake, Turbo-back exhaust) , had my plugs changed recently. the other day while entering the highway as soon as I passed 12psi of boost the car started bugging and the CEL started flashing. MY access port displayed "P301 Cylinder 1 misfire detected", "PFFF", "PFFE".
What has me puzzled is the fact that the car only misfires after I go over 11psi. it idles fine, and it runs fine even at high RPMs (as long as I dont pass the 11psi mark).
Please advise....???? thank you in advance..
swapped coil packs and the code moved! now Im trying to find a place that sells the coil pack with the least price margin.. thanks for your advise!Check out my post. Sounds like what happened to me.
Swap the coil packs and see if the code moves. Good thing its on the side thats easier to work on
I had a similar experience with my 02 WRX. During acceleration I would get a slight stutter and eventually a CEL with codes of misfires on 1 and 3. Took it to the dealership (after having it looked at by others) and they flashed the ECU. All has been well since.Hey All, wanted to share my experience.
My issue with Cyl 1 misfire started one morning out of the blue. My 2006 WRX (Stage 2 Cobb Access Port II OTS MAP) has over 150,000KM on it. It happened as I was merging onto the highway and I was pushing the car pretty hard on 4th gear. All of a sudden I could feel loss of power and the car was not running right. Check Engine light came on and the Cruise Control light was flashing. I limped her home.
Cobb Access port reported:
P0301 (Cylinder 1 misfire detected)
I reset the ECU using the access port and then swapped the Cyl 1 & Cyl 3 coilpacks.
Started up the car and no check engine lights but the car was still running rough.
I checked the troubleshooting menu and selected to read error codes and it reported Cyl 3 misfire (P0303 - Cylinder 3 Misfire detected).
Shortly after the Check Engine light came on and the Cruise Control light was flashing again.
I was happy to see an indication that it was the coil pack. I am going to be meeting up with someone in the next couple hours to buy a used coil pack.
Just goes to show you that a coilpack which never appeared to act up before can just completely fail, and it can happen under load and lead you to think that something far worse went wrong. It was interesting that the coilpack went from never reporting an issue to completely dead. I took off the boot, checked the spring, stretched it a little and put some dielectric grease on both ends, just to see if it was a simple case of poor electrical conductivity but no dice, it was toast.
Don't give up, check out as much as possible on your own before you take it to a mechanic or dealership. Donkey has provided a great sticky (Thanks !) to help you narrow things down.
Cheers and best of luck,