Tring to find a bad sensor

[bootlife]

What are we working on, what code numbers, any mods, how many miles, can you identify which cylinders are misfiring?

It's a 2000 Z71 new body, 5.3, bout 120,000 miles on 05 avalanche motor. Only mods is spectra cold air, screen removed on MAF, exhaust, and mid grade tune from Nelson. I can't tell which is misfiring. That's all it says I deleated the codes but ill make it doit tomarrow n get them. It has done it b4 with the old stock computer I had diablo sport on it then. But hasn't done it in a long time since the tune. But I can make it do it anytime now, seems like as long as there's no load on the motor it will do it from 2000 rpm up

[George C]

pull the plugs and read them, they will tell you which are misfiring

[farmtruc]

Get me a good long scan with various driving. No need to save multiple scans, just one big one. Save it as .hpt format so i can view it with the scanner.

No, not rich. ltrims indicate how much fuel the pcm is trimming or adding to maintain stoich. -25 and a rich code would mean it's running too rich because the pcm can't pull enough fuel to satisfy commanded.

Using hptuners, you'll be able to see individual misfires.