EGR?

[Shannen Durphey]

Dave Williams wrote:
> 
> -> Exhaust is an inert gas as far as an engine is concerned.
<snip>
> 
>  On fuel-injected GM V8 pickup trucks, disabling the EGR valve will cost
> 2-3 mpg, right off the top.  The first test a line mechanic does when a
> customer brings a vehicle in with a lost-mileage complaint is an EGR
> valve test.
It is?  And here I always asked "When was the last tune up" as the
first test. ; )

Shannen