SO last wednesday i got my timing advanced. Thursday i went down to cali for d1 drift series, mid day friday my cel comes on. I think nothing of it because when i got headers put on they didn't put in my rear o2's so i just figured that my ecu reconized that. During the day the cel would go off for about an hour or so then come back on. So when i got back to salt lake i took it to my machanic and he gets the codes, and I have the rear 02's which i knew would be there, but i also get a multiple misfire code. The car has been running fine, i haven't noticed anything wrong with performance. So i guess my question is wouldn't i noitce multiple misfires? and is it because of the timing advance?

They reset the codes and it hasn't come back on since. FYI

 

Don't worry about the multiple misfires....if you FEEL something wrong with the engine, then get it checked out....but as far as I know, me and a few other owners with headers always gets a 0300 code once in awhile...

 

Alright thanks andrew