My A4 is booked in to Prospeed next week to have the cat insides removed, & a pipe welded in to keep it looking OEM. Just wondering if anyone on here has decat'd there PD, & their opinion on the results.
I went to have mine remapped, the company refused to map it as they said the turbo wouldnt last long. I have now reoved it. They said without the cat the turbo spikesand will certainly fail.
I imagine they refused because they have generic maps designed for cat cars, by removing the car you make it freer flowing and possibly will cause issues, simply as they are not capable of adjusting the map to compensate for the cat removal. I'd suggest you go somewhere that actually maps rather than just flashes a generic map!
main issue with removing cats or larger DP is the back pressure which goes somewhere to helping sealing the rear oil seal, it only assist by having a higher pressure outside the turbo than oil pressure inside and thus pushes the oil/keeps it in. By making it freer flowing you reduce that and can cause oil blow by..