Not sure what gutted or downpipe is, how can I check ?The sound is very subjective. The best sound comes from a proper DPF delete downpipe. Is this what you have, or gutted DPF?
You can remove the back boxes, these are the only silencer in the 3.0 TDi system. The DPF blocks 95% of the sound as I had a straight pipe exhaust with no silencers, but retained the DPF and it was still quiet! So you may want to add straight through absorption type silencers in place of your back boxes.
I got 310bhp from remap and DPF still fitted. I guess yours is the older longer type DPF, I had a 2009 with the shorter type.
Yeah ?, the amount of smoke coming out of the exhaust is not missable, I’ll probably have to remove the blackbox or not sure what I you called it, what are they and what is their role in the carBasically, has the DPF been opened, gutted and welded back up, or have you had a DPF delete downpipe fitted. I'm guessing it's the former (there would be about £250 extra charge for the delete pipe) as you 'may' only pass the MOT with the DPF shell so long as the tester doesn't check too much or you know them?