Recurring, intermittent problem with reduced power mode on 2007 Colora

[ECB]

RECURRING, INTERMITTENT PROBLEM

Hi from ECB --- new member here. Love my pickup but it has a problem! Upon starting SOMETIMES the truck goes into REDUCED POWER MODE and the check engine light come on. After turning off the vehicle and waiting a few minutes the truck will start and drive normally but check engine light remains on for 6 to 24 hours. Then the check engine light goes off and the truck is fine for maybe a week before repeating the process. The problem occurs only during starting not while driving. Two other potential clues: 1) SOMETIMES when the engine starts the truck accelerates before gas pedal has been touched at all; 2) Fan that circulates air, heat and air conditioning sometimes seems to barely work on speeds 1, 2 or 3 but speed 4 works quite well. My neighborhood mechanic hasn't solved the problem. Later this week the local Chevrolet dealer's repair shop will be looking at the truck for a possible solution. Any suggests or information would be most appreciated!!! Thank you, ECB