Uphill stumble

this needs to be clarified if you really want to diagnose the issue. if you've ruled out hardware such as CPS, plugs & plug wires, cleaned your MAF, and if you were verified 04B13 then i would try an OV tune based off data logs. this is discussed in the OV MT thread and Alpha thread. that's throwing money at the problem but at some point you gotta get your hands dirty.

you can get your ECU scanned for free at Autozone. do not skip the step of verifying which ECU version you have. you can buy your own OBD scanner as well.OV's kit has software to identify it but that's the expensive route... but you get the tunes and a Tactrix cable as well as the future OV development. f i had cash to deal directly, then that is what i would do.

 

I suppose I could try replacing the CPS but it's still under warranty so don't feel like I should have to. Doing it myself would probably be easier than battling the dealer as I've done with the diff whine since day one. The stumble issue bothers me but doesn't bother me enough to spend $800 on an OV tune yet. Cleaning the MAF is easy enough, thanks for the suggestion.