Every other day or so I get a check engine light that says p0300 (random cylinder misfire), My ss/sc runs great all the time. The cel either goes away by itself after 5 startups or I get tired of looking at it and erase it. This only started happening recently when I put my new 3" exhaust on. other mods I have is 3" pulley #42 injects. ottp tune. When I really step on the gas is when it happens more often. Yes I have 1 step colder plugs that cam with my kit.

 

you might be running lean. ive seen it happen because of that. were your plugs pre gapped?

 

no I gapped my plugs to the recommended ottp specs. lean is unlikely because I get terrible gas mileage.

 

Just because you get terrible gas mileage it doesn't necessarily mean that you can't run lean

 

idk, it could be a possibility, but I doubt it. any other suggestions please?

 

i know that code is common with 60# injectors but seeing how you have 42's i dont know why you would get that.
check your plugs

 

I get it every once in a while, haven't gotten the chance to take a look at the spark plugs. Even if it is running rich or lean, the main problem here would be a re-tune correct?

 

most likely, do you have any way of logging your car?
if you do get in touch with someone who understands tuning/hptuners and im sure theyll be able to help you out.

 

Idk, I have a laptop scanner that I believe freeze frames and such, which would probably work.

 

you said it only started happening since you put your exhaust on. did you do anything to the header or downpipe

 

nope, just a catback exhaust.