Hey everyone. I have a 14" Fist I have had for about 4 years and it now has about 93k miles on it. As far as modifications go that may have any relevance here they are just a few basic bolt ons. A fmic, mountune filter, induction hose upgrade, hot side charge pipe, symposer delete, and a cobb AP with a few tunes.
I was driving a few days ago on the freeway and got into boost at about 2/3 throttle and all of a sudden the engine started misfiring. I turned around and drove home and read the codes and it was a misfire on cylinder 3 (p303) as well as a p0131 and a p0303 which I figured are likely from the misfire.
I pulled the plugs and replaced them and 3 and 4 were definitely gassy, the coils seemed alright visually. There is a lot of unburnt fuel coming from the exhaust as well. I replaced all the plugs and got the same thing. I figured i would swap the coil pack with a different cylinder and am having the same misfire at cylinder 3.
I read some of the basic readouts. The afr is definitely low at around 9-11 through various different rpms. The boost pressure is also reading negative and when I get on the throttle it doesn't seem to climb out of negative boost readings. Does this seem like it could be a vacuum problem or maybe an injector or valve issue?
I searched around a bit and couldn't really find anything definitive. This had happened to me about 4 months ago too when at wot when I was on my way home. By the time I got home the problem seemed to had corrected itself and had started running normal again. I pulled the codes then, and they were the same as the ones I am now having. It drove perfectly fine up until a couple of days ago. Any input would be greatly appreciated. Thanks!
I was driving a few days ago on the freeway and got into boost at about 2/3 throttle and all of a sudden the engine started misfiring. I turned around and drove home and read the codes and it was a misfire on cylinder 3 (p303) as well as a p0131 and a p0303 which I figured are likely from the misfire.
I pulled the plugs and replaced them and 3 and 4 were definitely gassy, the coils seemed alright visually. There is a lot of unburnt fuel coming from the exhaust as well. I replaced all the plugs and got the same thing. I figured i would swap the coil pack with a different cylinder and am having the same misfire at cylinder 3.
I read some of the basic readouts. The afr is definitely low at around 9-11 through various different rpms. The boost pressure is also reading negative and when I get on the throttle it doesn't seem to climb out of negative boost readings. Does this seem like it could be a vacuum problem or maybe an injector or valve issue?
I searched around a bit and couldn't really find anything definitive. This had happened to me about 4 months ago too when at wot when I was on my way home. By the time I got home the problem seemed to had corrected itself and had started running normal again. I pulled the codes then, and they were the same as the ones I am now having. It drove perfectly fine up until a couple of days ago. Any input would be greatly appreciated. Thanks!
