I Have a 04 Subaru wrx with about 53,000 miles. The current mods on it are;

aps 3.5 turbo back exhaust
forge blow off vavle
cobb intake
cobb short shifter

As of a couple weeks ago I have been having some problems. When I Step on the gas pedal all the way to the floor the car doesn't go anywhere. The boost climes to 14 psi and the engine sounds ok but it doesn't go that fast. When I hit around 5000 rpms the car finally takes off. (It feels like the worst case of turbo lag in the world). If I feather the gas pedal and slowly push it all the way down It goes fine. Also when I hit 6000 rpms my car just (shuts down). It stays running but it feels like someone cuts off the fuel. Im hoping that a well needed tune up including spark plugs and fuel filter will take care of this problem. Does anyone have any ideas what this could be???

 

If your car is a manual transmission, it may be that your clutch is slipping.

 

well the first thing is to take the BOV off, its pointless.you are loosing alot of boost with it on. we see so many come in to our shop with them and when they r back to stock its pretty much fine. also that you may be overboosting its a possibillity if you dont have an AP.