I recently purchased a 2006 PT Turbo with 106K miles. Did the timing belt replacement last weekend as a maintenance. Was relieved that the car started....and thought all was well. Also replaced plugs and wires (Champion at 50 gap.) I have been working on other things, like the brakes and heater vent cable and did not drive the car yet. It is still up on the jackstands. I fear my cam timing may be off. Today, after letting it warm up I noticed that the engine starts to fall off after about 4000 rpm. The car is in neutral and this happens with a gentle application of throttle. Seems like the Turbo wastegate may be opening, as the engine is not under load. If the car was being actually driven - Might that make a difference? But it is not happy after 4000rpm. As the car is new to me, I had not previously reved the engine in neutral with it's original timing belt, but had driven it up to 5000 rpm and it was smooth. So - any thoughts? Can someone reassure me that the cam timing is the fault? Sure seems the motor should rev smoothly past 4000 rpm - turbo or not. Has anyone else experienced this relative to cam timing being incorrect? Thanks for anyones experience with this matter. Just a little worn out and disappointed tonight. Tomorrow is another day, and it looks like I will be revisiting that timing belt.