well i have a miss fire again in my monte. i had on hand a new coil pack and plugs and wires do to the problems i had in the past with miss fires. it is getting pretty bad as in sitting at a lite i can feel a miss fire badly. i just put in new plugs wires and anouther coil pack and a new fuil filter to boot. i still have a bad miss fire the plugs are the ngk iridiums now in it. still missfires i am at a loss the plugs are corectly gaped new fuel filter new wires new coil pack again and the only thing i can think it could be a bad maf or a bad nock sensor but when i got a read out at the dealer there were no codes other than miss fire in cylender 2,3,4,6. i am stumped. i am at a loss on what it is making it do a miss fire other than the computer the nock sensor or the maf. thing is i am thinking what happend to it it ran beautifull befor the head gaskets went and after. i am at a loss on what is going on.

 

It could be a bad 02 sensor as well. What DTC's are you getting?

 

a tipical missfire code and check engine light for it. i dont get it i love the body but the engine is like if it is not breakin down it is throwing a code and doing a really bad miss fire

 

Well knock sensors usually don't go bad actually rarely ever. Are u gapping the plugs? Cause actually shouldn't touch them. Irdiums are way to soft that is why ngk puts a cardboard tube around threads so in shipping the gap doesn't change cause they are pre gapped to certain speck

 

Like Zipper said, look at your 02 sensor.

Question...does it do it only when its warmed up? or is it ALL the time.

 

it does it all the time most noticeable in the morning when i first start it and first start it getting off of a 12 hour day. how can a o2 sensor do that? i had one go bad and it showed the code for o2 on my mustang gt as well for the silzerado z71 that i have when i replaced them no more o2 error code?