help...My wrx is over boosting

[Myredwrx]

Hey guys! new to the sight. and first time Subaru owner, Ive just brought a 1996 WRX, with STI motor and running gear. good looking tidy car. wrapped as with it!
BUT...

Its over boosting, I was told it was the wastegate Actuator from my friend who I brought it of, So I replaced that with a second hand one. its still over boosting.

It lags allot when the turbo first starts to spool, then all of sudden it takes off! boosting up around the 20psi mark and that's only at about 6,000RPM

I noticed it back fires abit as well when decelerating.

It does have a chipped ECU with launch control and advanced timing and fuel/air ratio to suit 17psi, could it be that the chip is causing the ecu to play up??


any help would be much appreciated!

Cheers.

[Calvinball]

Are there any other modifications done to the car?

[Myredwrx]

Hey just afew minor mods...front mount intercooler, BOV, pod filter, 3" exhaust from tubro.

[zax]

How is the car tuned?

Beamed at your face at approx. 186,000 miles per second via DROID BIONIC

[Donkey]

Is the ECU controlling the boost? Is it using Ecutek?