hey i have a 2007 cobalt ss sc with a cai and ott stage 2. i installed stage 2 about three days ago. since then my computer has thrown the "multiple cylinder misfire" code three times. then this morning i hit the gas and it started missing, so i turned the engine of, popped the clutch on a roll and it ran fine. thats the only time i have noticed any kind of misfiring. someone told me it might be the computer relearning, i just wanted to get some opinions. thanks guys

 

I get that occasionaly too...
First step, I'd say clean and check the plug gaps....
When I got mine tuned, it was reccomened that I go 1 step colder on the plugs and use Copper core plugs instead of platnuim core.

 

i went two stage colder on mine. get colder plugs and check the gap. youll be fine its nothing major

 

When you did the ott stage 2 did you have to change the pcm or did they tune yours.

If you swapped pcm then you need a case relearn done by the dealer

 

the kit came with colder plugs by ngk.... and i sent in my pcm to get it tuned.

 

What gap are you running ? The LSJ can be picky about gaps .

 

my car has a similar issue. I had OTTP send me a ECU, but if you needed the case relearn...wouldnt your CEL be on?

 

i get the 300 and 171 codes occasionally when the plugs get wore out

2 stages colder is completely not needed

 

Definitely not necessary to go two heat ranges colder unless you are pushing around 300whp or more at least.

I would guess that the misfires are due to the plugs. Check the gap, if they aren't at .035 then gap them to that and try it again. Having too big or too small of a gap can cause misfires, etc.

 

I know some people wont believe this but when i was testing gaps my SS/SC with a 2.99" pulley and stage tune .......the motor would literally spit and sputter under WOT with a .040 gap . I then gapped the same plugs to .032 and the car smoothed right out and ran perfect. True story. I couldn't believe it either .

 

not needed but at the same time wont hurt nething either