I have a 2003 CTS I'm having trouble with and I'm not sure if it's a number of problems or just one. The Check Engine light is on and the code reader says it's the catalytic converter. The yellow Traction Control Off light is on and both the Traction Control switch on the dash and the control in the glove box do not affect the light. A couple of times, however, usually when I first start the car, the light is off and the controls functional, but it soon comes back on and the controls quit. The control for the left front window controls both the left and right windows, while the right front window control on the driver's side does nothing, nor do the controls on the right front passenger's side. Is it likely that I have several problems, or more likely that they're all connected to an ECU problem?

 

Seperate problems.

The trac light comes on due to the engine DTC stored.
The convetor is most likely no good. There is one for each bank of cylinders and should be covered by an 80,000 mile emmisions warranty.

The windows are on an different circuit and will most likely need to be diagnosed by a professional with the proper scan tool.

 

This is a copy [paste from another post - reagarding your windows:

My 2003 CTS did the same thing with the windows... the dealer said they don't know why it happens - but it does occasionally -- and the "fix" is to "reboot the car". I watched him do it. Disconnect the + and - battery leads from the battery; tough the leads together to clear the power from the system; reconnect the appropriate leads to the battery.

Apparently there are other electrical symptoms that can be fixed using this same method, but he didn't elaborate on what those symtoms are...