Check Engine light on 2003 Malibu

I have a 2003 Malibu that the check engine light keeps coming on (red). Today is the 5th time I've taken it back to the dealer. When I first 2 times I took it I was told it had something to do with the transmission but they couldn't get it to set off the code again so they weren't sure exactly what it could be. The 3rd time, they thought it could be the switch that tells the transmission when to shift so they replaced it. It ran fine for about 2 months and then the light came back on again. I took it back on Tuesday this week and was told it was a bad connection with the switch they had just replaced and they fixed that. Thursday the light came back on again. So, today (Friday) it is back at the dealer and they are still trying to "sort through the info" to find out what's causing the light to come on. Anybody else have this problem and if so, how was it resolved?

My 2002 Malibu is doing the same thing. We have already been through 2 new sets of rotors at $300 a pop. The theft sensor has had to be replaced, the blinker switch has been replaced, and now the engine light is coming on and when you accellerate it jerks like it isn't getting any gas.

So far I have changed all spark plugs with Bosch Platinums, and added fuel cleaner and fuel injector cleaner. I'm hoping the transmission isn't going out, and it's only a switch that needs to be replaced. I'm taking it to the dealer tomorrow to have it looked at. As soon as this car is paid off..you can believe it will be traded in for a better car

Also tried the new ceramic "quiter/less brake dust" brake pads. They don't work, that's what ate up the first set of rotors, they were louder than the originals, and my wheels were always covered with dark black brake dust, and this was in a 2 month period. Now I take my car to have the brakes checked about once a month. I'm not buying another set of rotors.