The problem has happened 2 times so far. I will be driving, the car is running fine and then all of the sudden the "Service engine light" comes on the "traction assist off" light comes on and it displays "Reduced Engine Power". When this happens the Tahoe will not exceed 20mph. We can park it and wait a couple of hours and it will be alright. Then it happens again a week later. I have already replaced the TPS after the first incident; which did not remedy the problem. I am out of options and no warranty left on the vehicle. It has 74,000 miles, and we have had the oil changed every 3k miles since we bought it new.
