Angry 2004 c class 220 cdi wastegate suden opening2004 c class Hi Guys im new to this forum and desperte for help . Firstly my car Mercedes c class 220 diesel aventgarde estate W203 registered 2004.155,000 trouble free miles until now. 4 weeks back accelerated up hill when the turbo waste gate opened fully rpm at time was around 300 and speed was 60ish mph turbo boost was registering 15.5 psi total loss of power but engine running stopped and switch off restarted and car was fine drove home with no more problems ,no engine warning lights .next day same problem , stop ,restart engine is fine ,zero fault codes found using cheap scanner.this fault is very intermitant can be here one day and not the next. Now being a retired old school mechanic i started doing the obvious checks IE turbo waste gate actuator found it to be sticking so replaced turbo with recon and recon actuator. still got the same problem .back probed the map charge sensor/the baro sensor /the maf sensor/the charge temp sensor / the exhaust pressure sensor/ALL are operating within the correct voltages and signal voltage. 3 days ago fault code aperied for the first time THROTTLE POSITION SWITCH. duley replaced with a new one and programed to ecu by merc with star sytem no fault recorded car drove fine for 2 days now the original problem is back .and fault showing TPS again .im now totaly lost any body experienced the same or can direct me in the correct direction thanks in advance Tony uk .UPDATE throttle butterfly is occilating when ignition is turned off before returning to WOT which i understand is the engine of default possition. That in itself throws me a curved ball becase ive never known another sytem that electronic throttle butterflys are in WOT when engine is switched off You would assume it to be fully closed on closer inspection the returm spring is designed to hold butterfly fully open so the stepper motor pushes against it still suggestions plse guys