My 2002 A6 1.9tdi 130 AWX avant returns just under 40mpg in mixed driving, but I feel this should be slightly higher. I do many steady motorway miles so would expect closer to 45ish. I know it's not a lot but it all adds up...! Using VAG-COM yesterday we read the MAF actual which stated it should be 210-350 mg/str, but was reading live at idle with the engine warm at around 550. Does this signify an issue or is that about right? Aside from that the car is running great, although does have a "boomy" rumble around 1500-2200 rpm which sounds like something somewhere is very slightly off balance or a sensor is slightly out. I've tweaked the remap to lower peak torque around this area which has helped but certainly shows something may be off. The MAF would just be a nice easy part to swap out to try first!