ok, my car has been playing up for a few weeks, stalling and not staring again without lots of throttle, over fueling, and just generaly driving lumpy, so much so i cant drive it, ive changed spark plugs, leads, and fuel filter, and the fuel filter made it run worse. anyway got a vag-com reader today and the fault codes it pulled up were 00522 engine coolant temp sensor 00537 oxygen sensor control 00513 engine speed sensor what do i replace, all of them? and if so can anyone tell me if these are easy jobs or should i pay someone to do it for me? any advivce would be gratefully apreciated *