Vacuum leake on 97Z

[danjo11]

I need to know the best way to check for an air system Vacuum leak. I have recently replaced a couple O2 Sensors and both ERG valves. I am still getting codes for a vacuum leak. (the gas cap is fine). Can someone point me in the right direction on how to check for a leak? Thanks for the help.

[murche]

shbox.com has some vacuum diagrams. Get a hand vacuum pump with a gauge from an auto parts store for about 20 bucks, isolate lines and start checking for leaks

[Knight]

Isolate each line and spray with starting fluid. When the idle raises, you'll be able to pinpoint the leak.

[texas97z]

x2, shouldn't take very long. Might also want to spray along intake manifold, but FYI if your's is painted it will take the paint off and you will be doing some touch up.

[transamtom]

Both EGR's?

There is one EGR on the back driverside of the intake.

Do you mean the Air Diversion Valves on the exhaust manifolds?

The intake manifolds are notorious for leaking at the back.

They cast the drip rail on the manifold too short and you blow the RTV sealant out.