I have a boosted 2000 civic si with a built bottom end and a 95 gsr head. The car is tuned on 25psi but right now its on 15.. when i floor the gas and reach to 1-3 pounds of boost it starts to splutter. and when i got the car tuned(street tuned) everything was fine until i drove it home. and another thing is my idle surges from 1k to 1500, and sometimes 1k to 200.. could it be my TPS? or IACV?

 

Check for vacuum leaks/boost leaks, check you IACV and TPS. Any CEL's?

Let me get this straight, you had the car street tuned on 25psi, but never tuned on 15psi?

 

i have a manual boost controller, so yeah i can set my boost. the CEL comes on randomly, i can turn on the car and 15mins later the CEL comes on then when i turn it off and turn it back on it goes away and doesnt turn on for another 2 days.. we checked leaks, there were none so imma change out the TPS and IACV tomorrow

 

A copy of this thread has been moved to the Forced Induction section.