What causes boost creep?
 

As title suggest, I think I have a problem with boost creep. MY96 WRX Wagon, with td05 fitted, decat and full system, Scoobyecu reflash chip.
Boost gauge seems to hit 18-20psi causing fuel cut, when boost limit is supposed to be around 16psi....
Any ideas guys....

actuator or wastegate spring is not strong enough, after you install a decat system your exhaust flow increases so the stock spring is no longer enough to open the wastegate

Is it bell mouth decat or the 3 inch to flat plate type? Porting the wastegate will help

The decat pipe is a fully open type(not sure what it would be called), the cat pipe had only half the pipe accessible.
How would the wastgate/actuator be ported?

You need to check that is the problem first. Check the actuator and check wastegate opens and closes freely.

I know the actuator is ok as the turbo was only fitted a month or so ago. The wastegate did have a little rattle on idle, the flap was a little loose so the actuator rod was adjusted to stop this. Could that adjustment have caused a problem with the wastegate not working correctly?

If its over adjusted it could. Are you running a 2 or 3 port boost solenoid?

2 port as in 2 vacuum pipes? Red pipe in, black out? There other vacuum pipes on the unit...


http://i1058.photobucket.com/albums/...69F47DCFD4.jpg

This the actual one on the car....

Looks like a two port. A three port would probably give more control

Any ideas how a 3 port would plumb in, as this one only has 2 pipes...?

If I adjusted the actuator rod, would it need to be tighter or looser?