Doddy

Steve, you're pretty much paraphrasing my thoughts. I was watching a video of an A6/B9 with the EGR on the underside of the engine - I thought separate but lower than the DPF (and turbo - closer to rear of engine bay) - either way a complete mare to get to and explains some of the information of removing the wheel/driveshaft to get to it. Petrol and Japanese?, again, exactly where my thoughts were heading. Thanks for your view - genuinely appreciated - it feeds the devil on one shoulder whilst eternal hope feeds the devil of the other shoulder to repair. If I'm being honest I think you're right, though. A shame because I have enjoyed this car, but...

Kath, thanks for the reply. Although I can squint into the engine bay and compare that against some online B9 workshop manuals it's still very difficult for me to observe the routing of the EGR cooler pipe and where the pipes are routed - so knowing that yes, it's feasible to DIY. Double jointed wrists, though - that's a young man's game. I was of the thought of a lot of YouTubers that I've been watching that removal/cleaning/assessming the EGR would be the best first step, but realise that much of the cost/effort is in the labour. But if it was just the cooler or the valve then an ultrasonic tank filled with some interesting fluid would be my first call. I wouldn't baulk at a replacement valve but as you say the EGR/Cooler is a single part from the factors (and from the quote I've got is somewhere between 'whoah' and 'eek' (still less than a grand and if that bought me another year on the car I'd be happy). DPF?, Just because internet wisdom for P0401s suggested the DPF, together with the age/mileage - it's where I started. I'm moving away from that diagnosis (perhaps the Internet isn't always right?) having talked this through with an Audi buff (with a 2 post lift) - it was originally the reason I took it to a DPF specialist but they ran it around the block, pulled the codes, quoted for EGR, and helped me lose 150 pounds from my back pocket within the space of an early morning. I am getting frequent regens but I need to isolate that from this EGR issue, I think, I've never seen a DPF fault code. I am now running with DPF/EGR snake oil in the fuel tank, and of note all this started shortly after I resigned/retired from work and my mileage dropped to single-figures daily - coincidence?

Kath, Apologies for thread necrosis, however, I'm banging my head on the wall over a 2016 B8.5 (engine code DEUA - so appreciate I might be comparing apples with oranges) with the same fault code - quoted £2.6k by a local garage/DPF specialist for replacement of which £1.5k is labour ("engine out job, mate"). Together with known extra work for a DMF replacement, 93k on the DPF and the inevitable timing belt it's uneconomical for me to push it through a garage...I'm just trying to drag the car a little further before scrapping it. You (OP) suggest (or I've interpreted) that you did much of the work yourself - is this true and if so just how difficult a job is it and how long did it take you? Any online resources that you found that were useful?