PWR reducing

My dealer can’t tell me why my '06 Cobalt keeps entering limp mode or why there’s no code. He says he can change out the throttle and the gas pedal. They’ve taped some wires, and put in a new computer; but it still sounds like a short to me.

Usually happens in the winter after driving about 40 miles.

You need to give a better description of “entering limp mode.” What - exactly - happens and under what conditions? If it is literally entering limp mode then there are codes. The computer puts it in limp mode when it sees certain kinds of problems.

How many miles are on this car and other than oil changes what is the basic maintenance history (e.g. plugs, wires, filters etc)? Is it an automatic of a manual?

Other than trying to read codes, what has been checked or tested? How did they get around to putting a computer in it, for example?

Going into limp mode and no codes are show? Really? Are they using the car-specific scan tool, the one designed by the manufacture to diagnosis this car, or a generic scan-tool? If a generic scan tool is used, it may not be able to access all the codes. Transmission, ABS, ESC, codes for example might not be seen if the wrong scan tool is used. Since you are going to a dealer shop, you’d think they’d be using the correct scan tool, but wouldn’t hurt to ask.