ok so my wife was driving our 2002 audi A4 1.8T today and suddenly it starts idling really rough, hesitating to accelerate and the check engine light flickers on and off. Right before this happened (we have only owned the car about 6 weeks), we got the oil changed with SAE0W-30 castrol synthetic oil @ oil can henry's and they ran their engine sludge reducer through it before the change, we also had the brake fluid topped off by a reputable audi service location and the brake light switch and L shaped vacuum hose replaced. I'm thinking that the oil sludge treatment chemical loosened up some sludge and clogged the fuel filter.
Also, the car ran fine (better than fine actually, I noticed better acceleration and improved idle) for awhile after the work, then it sat several hours and then my wife ran to the store and that's when the symptoms presented. Any ideas? As I said, I'm an Audi newbie, but I'm feeling clogged fuel system...