Hi guys I have a 2001 Denali with approx 220k on th odometer. Today while driving the idle would fluctuate between 1500-3000rpm while I was driving on the expressway. When stope at a light the car would idle at 500-700rpm. The trans also had and issue upshifting until around 3000rpm. Trans was rebuilt @ 5k ago, so I'm pretty sure its not an issue. This all started today. I'm about 75 miles from home, but I don't want to move my car and risk being stranded. Any insight would be greatly appreciated.