I am doing a rolling road in january and want to get the car running as well as possible, looking through the how 2's I have a little list of bits I want to do, I want to clean the egr valve, replace the egr gasket (thinks mine is goosed as I have a leak on top which I have been told is either the injector seals or egr gasket) replace leak off pipe, replace injector seal, clean boost sensor. Is there anything else I could clean/replace(if a cheap replacement) to get the car running as smooth as possible?