Code P1668 after buzz test
I bought a scan gauge from TE a couple of weeks ago and had trouble with it completing the cylinder contribution test and the buzz test. Kept coming up as unable to complete test. Well, I was showing the gauge to a friend today and it finished a buzz test and came back with p1668. I know about what it means, but where do I start for trouble shooting? Is that the reason it has been having issues completing these tests? This one is new to me....tell me what I need to/should know.