Pulling timing? Misfire?

[targett27]

I've been having problems with my gst. when I hit anything more than about 2-3 psi the car feels like its pulling timing, if I keep giving it gas it will start to sound like its misfiring, almost the same sound as two step. I can't find any boost leaks, i've replaced the plugs and wires with ngk 6's and I've replaced the knock sensor. Any ideas on what the problem could be? Thanks in advance.

 

[delta448]

I can't find any boost leaks

Did you really test it, or just tighten some couplers?

i've replaced the plugs and wires with ngk 6's

Are they gapped to 0.028"?

Any ideas on what the problem could be?

Running too rich.