95 S500 w/230k miles. I've read about the EGR Switchover valve and the fuel pressure regulator. I had the codes pulled and my dealer indicated replacing the engine harness would be the answer....it wasn't. My check engine light is on and the car has extremely long cranking times, particularly after the engine is warm. My air pump is starting to make quite of bit of noise when engaged. Could that cause hard starts? The engine will miss every once in a while, but not often. I've done the complete tune up and even replaced the mass flow sensor (which taught me to always have the air filters in place when working on the car). I don't see raw fuel around the vaccum line at pressure regulator. Will a faulty EGR valve cause this? Can you clean the EGR valve? The air intake sensor (in the air intake hose on the driver's side) needs to be replaced...will this cause significant problems?

Any and all advice is appreciated.

Thanks!

__________________
Lyndon T

91 300 sl
95 S500
97 SL 500