Poor Performance is always a tough one to track down... just one of those "replace items until problem gone" situations.

Check wastegate for solid operation. Also check anything that has to do with mixture. This includes:

- Air filter
- Fuel Filter (PITA to replace, I leave it to my indy)
- Fuel Press. Reg.
- Post AMM turbo hoses (amm to turbo, turbo to inter.)
- CBV connection and hoses

Make sure you are running a high octane in your turbo since, under compression, pre-ignition is much more likely with a lower octane. Additionally, you only save about US$2 with cheap gas per tank, so it isn't worth the poorer performance.

If none of that works I would look at the mixture related sensors: Knock Sensor, AMM, ECT, and o2. First thing is to just disconnect, slightly clean, and reseat the harness on the sensor to make sure it isn't a connection problem (you'd be surprised how a slight shift can screw things up). Also check the wiring for deterioration or shorts. If it still doesn't work get a multimeter and start checking resistance on each of the sensors per spec (which you should be able to find in the FAQ).

good luck,
rt