i'm looking for some suggestions / help with an issue i have with my 1.8t
At WOT the car will start to build boost and take off as it should, but at about 4000 RPM, the boost dies off and i get the 5 psi soft limp until i let off the throttle completely and lean into it again.
The car will build up to the 20 Psi it's supposed when the car is driven down a somewhat steep hill but that's the only time it will reach 20 psi.
the car idles fine and other then a lack of boost under load, it drives normal and i have yet to hear a misfire.
the other thing Ive noticed is if I'm at WOT and let the gas pedal off right when it usually drops to 5 psi, i get the fluttering sound from the diverter valve
Parts Replaced \ Upgraded :
Forge splitter valve
brand new OEM MAP sensor
2 New coolant sensors
Newer spark plugs (gapped to .028)
new air filter / oil change
Unitronics Stage 1+
Steps Tried :
Visual check for boost leaks
Visual inspection of wiring harness / connectors
cleaned SMIC of oil
Tried unplugging MAF, no change
Checked for Codes ( NONE :S )
Fixed exhaust leak after CAT
any help would be appreciated, I have VAG-Com and have some knowledge on how to use it.