Originally Posted by HKMark23

This thread reminds me of my (comical) early experience after installing my OPG. On cool startups my gauge read, (and still does), close to 40 psi. First time, during a particularly hot run, I noticed my OPG it was reading almost nothing at idle. I damn near **** !!

The value in these things is in getting to know what typical readings are when hot, cold, at idle, and running so atypical readings can tip you off if something starts going wrong.

They aren't magic but better than the "you're fvcked now" light, IMHO.