RB20 Horsepower loss at high RPMs.

[Monkey87]

I've recently swapped in my RB20DET without many problems. I was happy with the numbers it produced on the dyno, at 192 whp and 180 wtq. These aren't far from the numbers an R32 skyline dynoed. Now, after a few weeks of running fuel system cleaner and seafoam through it (not at the same time, mind you), it's started to run like crap. After 5000 rpms my horsepower drops, and I've also noticed a low-end torque loss. I've checked for boost leaks, oil leaks at the turbo, etc. and there is no sign of trouble.

Any idea?

[Cjmartz2k]

Change the plugs and quite running that injector cleaner crap. I'll bet you a diet coke you pull the plugs and they look all pink/orange.