While driving or idling, vehicle displays error messages stating "reduced engine power", "stabilitrak system disabled" and "service traction control." The engine power reduces and the vehicle hesitates upon acceleration. It is difficult to get the vehicle to accelerate, especially in lower gears. Sometimes the vehicle completely loses power in the middle of driving and all control of the vehicle is lost. Now no fuel pressure. 07 Tahoe LT 5.3 flexfuel Any insight would be appreciated