I have a buddy who has a 2005 Caddy. When he starts it the idle speed goes up and down, but this does not affect the performance. I thought maybe it was an oxygen sensor. Anyone have any other ideas?

 

idle speed controller .. 99% sure.

 

Thanks, I will let him know.

 

Just got an email from my buddy. He just got his car back from the garage. They reset the computer and now everything is OK.

I just wonder if it will last or the problem will show up again later.

 

that is no so common, but it does happen

what i have seen as most likley issues are:

- ISC,
- coke buildup in intake throat
- ignition issue - coils, wires, plugs, etc,
- emissions controls issues
- grounding issues
- ECU
- valve issues
- etc ..