Backfireing? help!

[BigRb247]

OK I have a 3" full exhusat and recently , had it put on a lil while ago, it has been liek backfireing or at least it sounds like that when i hit 12 psi , which its set at. It like poips reall loud constantly. Can someone tell me why that is. IS it cuz there is very little back presure or what? help!

 

[RallyxDave]

My guess is that your engine is missing under boost. Check your spark plug gaps and the condition of spark plug wires. Problems with either of those will cause misfires under boost.

 

[BigRb247]

Alright il try that and let you know how it goes, but i was just wondering what gap i should set it at. I mean i know there is certain gaps for certain cars but what do you guys have them at? and if this doesnt work what else could it be??

 

[nine5raptor]

~.028-.030" also if you are using platinum plugs, replace them with copper ngks