Feedback 4.2tdi backboxes removal findings! All good

[jonnypym123]

Ok guys thought I'd give some feedback to anyone interested on what I found with tuning the D3 4.2tdi and removing its back boxes.

I got her last May after having a nasty crash in April in my 2006 A8 D3 3.0tdi after aquaplaining and the car had to be written off, tbh I felt gutted as it was my pride and joy but no one was hurt which was the main thing. Since getting my new A8 in May I had it tuned a decent tuner in Sunderland after a previous tuner diagnosed it as "already tuned" with turned out to be bs and were trying to get out of tuning it. Initially it was down on power on the dyno at 299hp/630nm and they managed to get it to 340hp/866nm ( apparently they tried to get it higher but it may have been due to carbonisation the low hp figure).

Even after getting this remap done I felt it could have more potential as I always felt it lacked that initial kick in the back sometimes. I had my exhaust backboxes removed last weekend and replaced with stainless steel straight through (still have dpfs) just as I had on my previous 3.0tdi, however the 4.2tdi now feels like a completely different car after circa 500 miles since getting it done, the difference is day and night, it's more responsive and definitely feels fast at accelerating, the exhaust tone is nice as well, no resonance at 60mph, can hear it just slightly increase in exhaust tone cruising on the motorway, under hard acceleration you can hear it and sound great. There's a few videos online on people who have had it down with the dpfs out as well and it's pretty similar.

Anyone who's got a D3 4.2tdi I'd recommend doing it as It has made the car more enjoyable to drive who would have thought those metal cans at the back made so much difference.