i have a 2006 a3 with 86XXX miles on it, did routine maintenance on it, had coil replace under warranty, but only when hot the motor sputter a little and idle it rough. i have been reading about the pvc and diverter valve causing issues with boost, is this a good place to start? i know the age and harsh environment they are in it could not hurt it have been an excellent car and want to keep on top of things. any help will be appreciated, also what is to much oil residue in the charge side ducting, if any?
thank you everyone