Swapped my ls6 for a fast 78mm intake and now im throwing a p0300 code random or multiple misfire. Anyone else experienced this, maybe one of the rear vaccum lines came unplugged again, although i see alot of the small vaccum lines capped off on some modded cars with no SES light. or could the difference in air intake with the fast be causing this and mayb it will go away after i re tune it. Can anyone chime in?

 

Does your car run lean??? thats a Missfire code.... Check all the vaccum lines... A friend had that same code throwing on her mazda 6 and it turned out her bank 1 had a missfire and was running lean as ****..... Im pretty sure other will chime in on this... Your gonna need a tune no doubt...

 

anyone else have any insight. i checked all the connections and hoses and all seemed fine. The next day the p0300 code went away and i was then getting a po174 i think. System too lean .Then a few days later that went away and now there is no SES light. Dont know whats going on.