I know we have some smart people on here. I’m about to lose my mind with this SUV.

2002 Escalade. Keep getting reduced engine power. I’ve done the foot pedal sensor, TPS, and TAC Module (a good used one). I’ve changed batteries, cleaned the grounds, load tested the alternator. Checked all the connections and wiring. Half *** checked voltage at the plugs. I’m not sure it’s a wiring issue though.

It seems to be temperature related. When you first start it up it will continue to go into limo mode. But if you let it just idle for 5-10min. Shut it off then start up. No limp mode. Then when you go to drive it. It will do it periodically. When it’s below 55* it acts up. Continually. But when it’s warm out. You can drive it all day long even 3-4 days or so without a single issue.

I’m getting P1515 and P1221

Help, someone.

I had a similar cold weather issue. My 2001 Silverado 5.3L would cough and die upon startup when parked outside in cold weather. The check engine light would go on but then go off by the time I got it to Autozone to get the code read. I did a new MAF after reading forums, had no effect. One of my buddies said it was probably a vacuum leak from worn out intake manifold gaskets.

I replaced the knock harness, knock sensors and intake manifold gaskets which completely solved the issue.