99 Tahoe dies

[Eric Wettschreck]

5.7, 210k miles. Codes coming up are #4 cylinder misfire and EGR fail.

This is my neighbors rig.

This thing has a ton of vacuum. He checked the PCV valve and said it's good. While running, if you take the oil fill cap off the motor will die.

I know the EGR code is coming up but would a faulty EGR valve make it die like this?

[Jeremy airjer W]

What does the number four plug look like?

Does it use a lot of oil?

Remove the breather hose from the intake tube and attach a vacuum gauge to the hose and plug off the opening in the air tube. Pinch off the pcv valve hose (if it is rubber and not plastic). Start the engine. If you see vacuum at 18+ you have an internal vacuum leak (lower intake gaskets?).

[Eric Wettschreck]

Thanks Jer. I'll let him know.

[Eric Wettschreck]

I wasn't there, but my neighbor told me the vacuum was well in excess of 18 inches.

Looks like he'll be working on a lower intake.

Thanks Jer.