ajg617

2003 A6 Avant 3.0 quattro with 104k miles on it. I can feel a slight miss now for about the last 3k miles at idle - more like a rough idle - definitely not like a bad coil pack. Coil packs, plugs have been changed as has the fuel filter. Running a fuel injector cleaner for the second time but doesn't seem to make a difference.

The only code I'm getting is for the bank 1 cat. So my question is can a bad cat cause a rough idle? I've cleared the code a couple of times and it seems to smooth out the idle but when the cel comes back on, I notice the idle gets rough again. Other than that, car runs fine and fuel mileage is where it should be.

4Driver4

No.