I have been curious as to what the lifespan of the smog pump and it's related components are on my '95? Is there anything related to this system that needs regular service or will the CEL come on if something is not right? I plan on keeping the truck all original so was just curious as to when I might have to start looking to repair this system. I only have 48,000 miles. Also, does anyone know when the egr valve is supposed to open and close? The reason why I ask, the other day when I was servicing the truck I noticed when I was reving the engine via the throttle body and looking at the egr piston it was moving up and down. I thought the egr only operates while driving. Thanks in advance.

 

My 95 has 214k on it and the air pump is original. The EGR valve will move once the engine is warmed up and the engine goes above idle speed.
regards
rikard