Ztevo93

So, i have an 03 oz rally 5speed 165k and have aquired a misfire but only while driving. Most prevelent in 1st or 2nd gear. While letting my cat warm up after work it finally popped a code the infamous p0421. The only recent work i have done is change spark plugs and belts about a week prior to the misfire started to happen. I have researched the code and i am well aware of the issues with the cat. I have not seen anyone having a misfire with this code. And i can not imagine the cat would cause a misfire all of the sudden. The car idles perfect though and revs smooth. Thank you in advance for the help. I am a diesel mechanic and have a good understanding of how things work but cant narrow this one down.

02modlanceroz

iTrader: (2)

Any other codes? Does it throw a misfire code, and on what cylinders?

Ztevo93

Sorry for delayed response... But, over the next day or so it got worse to where it was a constant jerking but not a misfire on one cylinder.. Hard to explain but the misfire was not every revolution of the engine. It was major jerk about 2 times a second if i was guessing. Eventually threw a p0102 code for the MAF sensor.. Cleaned sensor car runs like a top.. Never would have imagined those kind of symptoms to be a dirty MAF. Can never be to humble i guess