Ivaan

I think I've answered my own question above. The exhaust box is the Catalytic converter, with the oxygen sensor. The DPF is located further down the exhaust system under the car. Found this information in the SSP-325.pdf linked to in the sticky at the top of this forum. Very useful. Now I know it's not a DPF issue ( car doesn't have one ), I'll remove the turbo and exhaust link pipe to examine.

Did you ever resolve this problem? I now have similar, so looking for answers. Cheers, Clive

Hi all, Hope you can help. My A6 Avant 2.7tdi 2007, has the PR code 7GN ( Emission standard EU4 DPF preparation ), so I assume it doesn't have a DPF to get blocked. However, when I look to the rear of the engine, passenger side, there's what appears to be a DPF filter box on the exhaust about 12" below the turbo, by the passenger footwell. It also has a sensor fitted just above the DPF. Is this just a dummy box with nothing in it, or is the code incorrect and the car does actually have a DPF fitted? I have exhaust fumes coming into the cabin, but it's difficult to see the source. It could be the pipe from the drivers side exhaust manifold, going to the bottom of the turbo, leaking from the flexi-joint, or it could be the turbo itself, or, I'm told it could be a blocked DPF, hence the question above. I also have oil in the fresh air inlet side of the turbo, which could point to a leaky seal somewhere or a blocked oil drain from the turbo. Car still goes well and pulls fine ( 145,000 miles ), but this past ( covid ) year has been mostly short, infrequent, journeys which is probably not good for it. Thanks in advance.