I used This thread to get our 2003 Yukon running . It was shutting down to 1000rpm, no power, and Check Engine Light on, with the Reduced Engine Power message. Wife was able to get it home by restarting it three times. This morning, while the engine was cold,no tried to tighten the grounding cable bolt on the block, it was already tight. Then tightened the small battery posts on the side of the battery. Both were about 2/3 of a turn loose. Which is kinda loose since I'm an old guy with arthritis,no was cold,band I used a 1/4 inch ratchet. So they still may be loose for you young folks. Hahahah a. Then,in took out the KandN air filter, which I probably had too much oil on. Shot 10 seconds of carburetor cleaner right thru the screen in the air intake, then same amount of Mass AirbSensor Cleaner thru the screen in the direction of the air sensor. Then I put an OEM Purolator Air Filter in. The Beast started right up, engine light is off now, and it runs better than it has in a while. There is a lot to be said for OEM parts and Air Filters,band cleaned up sensors.