Hi, I have a 2004 Audi A4 1.9tdi. Yesterday in normal driving conditions, driving @ about 60 mph, the emission control system light came on and the glow plug system light started flashing. The car was still driving fine and no overheating or funny noises. Any suggestions as to what the problem might be and how to fix it without having to take it in? I read about similar problems and someone said their DPF filter got blocked and that this now needs to be cleaned or "regenerated" Does my car have a DPF filter? And if not, what else could the problem possibly be?