Do i have a boost leak,? when driving my car everything is fine unless i try to start building boost. and if i do that, my car sputters and shakes. but if i put my foot in it. It boosts to 15 psi and it rans normal.

 

whats your mods?

 

drop in k&n ams FPR megan exhaust headers. and walbro 255

 

make sure the piece that directs air into the airbox has its fasteners in it. if not it will cause the problem your talking about

 

check all the couplers.. sounds like a boost leak to me

 

it could be that your coil pack went bad or simply just replace the spark plugs.. my bet is one of them..

 

How about doing a boost leak test? It takes about 10-15 minutes to do.