check engine light is on my 1996 z28.the code autozone gave me was p0400
said it was an egr valve.so my next question is where is the egr valve located and if it is easy to get to.also they want $59.99 for it at autozone any better prices pot there let me know thanks in advance.

 

The EGR valve is bolted to the back of the intake manifold. You remove the two nuts that hold the valve to the studs in the manifold, unhook the vacuum line. I think its 13mm on the nuts. Hard to reach.

Courtesy of Shoebox:
http://shbox.com/1/egr1.jpg

If you are running a low back-pressure exhaust, no cats, etc. it may be contributing to the problem.... not enough exhaust gas flowing back into the intake manifold to satisfy the diagnostic routine, which looks at MAP change when the EGR valve is closed. A new EGR valve might not solve the problem. It could also be aggrevated by carbon buildup in the intake manifold passages, or on the pintle of the EGR valve. Might want to remove the valve and try cleaning it before you buy a new one.

For GM parts in general, at 1/2 off dealer list + shipping, order from Jason Cromer or Dal Slabaugh. Do a "search" for contact info. Also look at gmpartsdirect.com, but their shipping can be excessive. Should be able to get one for less than $40 all-in.

 

thanks alot Injuneer,it does not look fun but atleast i know where it is now.