I bought my car with 11k miles ('04 STi) The car was bone stock except for a samco intake pipe. The car was missing clamps at the intake pipe, and the turbo to intercooler pipe. I clamped everything up, but noticed the turbo to I/C pipe ( Y Pipe ) Is a bit chewed up. I installed a boost guage and am only getting 9psi. I am hearing a weezing sound instead of a typical spool sound. I am thinking 2 things :

1. The Y pipe is shot, and is leaking boost.
2. There is an exhaust leak at the turbo/dp

The car still runs kind of nice even with 9psi, but I know it is not sounding right, and should be making more boost.

no CEL, any suggestions , idea?

Does the turbo hold 9psi nice and solid? If so, maybe you need a "brass restrictor"?

peace

Do you have a compressor? If so, make an intake leak tester out of PVC, a PVC pipe cap, and a tire valve stem or a compressor junction. Remove MAF housing and insert pipe. Set the compressor regulator to 0 psi. Atttach hose to valve stem or junction an then gradually increase to 15 psi. You'll hear an intake side leak if there is one.

Frank

replace any hoses that look chewed up as you say, make sure everything is tightened down and you have no intake leaks. a small exhaust leak shouldn't cause you to lose that much boost (you're missing around 6 psi). Make sure everything is tightened up and leakie, and if you're still only getting 9 psi report back.

and whyis this in the AP section if you have no EM? and why would you turbo > DP not be tight if you still have the OEM DP?