It only does it when its hot. Once fully warmed up it does it.

Car runs and drives fine. I can boost at 10 psi all day. But once I push it to full it backfires. And not a little... ALOT.

Went for a ride with friend and he turned off boost cut and fuel cut. And it still did it.

I also took off my intake and tried a differant mass.
Checked gap on spark plugs. 2 where a little off I regapped them to .020.

Only mods are 3 in full exhaust no cat.
Stock boost

Only things I have left to try are:
Maybe change plugs.
boost solenoid
Take off exhaust and take to dealer.

 

Check to make sure the MAF sensor is connected. Dunno if you might have removed your filter box and maybe forgot to reconnect. Did this start happening immediately after you added the exhaust?

 

do you ahve a wideband or know someone who does? Have you done a boost leak test?

 

yes boost leak test is a must. do it and if you are leaking boost then track down the leak and fix it. its easy it happened to me once....

good luck

 

boost leak test ftw!

 

You are not boosting 10psi. The stock WGA minimum PSI is 13-14psi.

 

Sorry I forgot to add we did a boost leak test. We went up to 20psi and nothing.

The car sat for a week. not being use once. Then it just happend.

 

I mean I can boost at 10 psi with no issues. But once I push it to 20psi. It backfires alot.



Thanks for the replys guys. Keep em coming.



Anybody think changing the plugs is a good idea??


Thanks
Casey

 

depends on which plugs you are running and what they are gapped at. To much gap can cause the symptoms you are having.

 

checked plugs. stock plugs gapped at .020

 

wow... thats tight. did the plugs looked fouled at all? It wouldn't hurt to swap in a set of NGK copper plugs and see what happens.

do you have any logging tools or are you getting a CEL?