What is the EGR valve on a 1992 Chevy Caprice Classic?

Answer 1

it's called a Exhaust Gas Recirculation valve.

In a 92 it would probably be located just back left of the carburetor, or throttle body, whichever you have.

Kinda looks like a steel mushroom with a vacuum line connected to it, you test it basically by reaching your finger up and under the egr valve itself, there's a few holes big enough to get them into and try to push the damper up, and see if she slides up and returns smoothly, if not, or it's stuck, replace it.

It's function is to recirculate the warming gas fumes in the engine as your car warms up, hasting the process, promptly should close when the engine temp rises to normal, the hot gas is then shot out the tailpipe instead, when it fails, it stays open or closed, causing gas circulation through the engine indefinitely or not at all, the first explination will cause gas guzzling and poor performance.

jr