1992 GMC Yukon...128k miles...runs beautifully. Power chip installed many years ago and has always passed smog...always run super unleaded. All visual tests passed, but "NO (PPM)" max is 683, and th
Let me know your thoughts please.
Cars & Trucks - GMC - Yukon - 1992 GMC Yukon
Answers & Comments
Ck the o2 reading with a scanner that will give you live data,ck and see how fast o2 switches from lean to rich, if its slow the o2 sensor may be sluggish and feeding bad info to the ecm. new ones usally solve this