My 1990 feels like it lost 100hp all of a sudden, has started bucking, and throwing CEL's. I can build a full 16psi of boost, but the car goes NOWHERE. It feels like an intermittant IC piping leak or slipping clutch, but is neither. The CEL will come on and turn off randomly. There is a little bit of idle surge sometimes.

So far, I have:
-replaced MAF
-replaced ECU
-boost leak tested (Very small leak from compressor to turbine side, no shaft play)

Maybe a sensor somewhere?... the engine sounds good. IAC? TPS?