i have a 2003 esclade with 6L and i get the reduced engine power problem for no apparent reason. It will happen once in a while and then go 2 or more months with no problems. if I shut the car off and restart it sometimes it will go off. but sometimes it will have to sit for awhile before it recifies itself. I am worried that it might happen to my wife while driving on the highway. I have checked all wires for breaks and connections are tight wiring looks brand new. anyone have any ideas? Money is super tight so I can't afford a hit and miss approach. Thanks for all your input

 

How many miles do you have on the car? You might want to check the catalytic converter.