Has anyone else had any problems with their 4.2l supercharged rrs not having much power above about 4000rpm? I've noticed it since I've had the car which is about 12 months but today I noticed it was much worse so I had a look at some live values while driving it hard and noticed that everytime it happens, the throttle position sensor reading drops from 78% to about 52% while the accelerator pedal reading doesn't change. What I can't figure out, is whether the throttle position is being changed by the ecu because of something else going wrong, or the throttle position sensor just needs replacing.