034Motorsport High Flow Catalytic Converter - Audi A4 B7 2.0TFSI

Been pondering this upgrade for a while. Bought this with the DV+ and installed at the same time. I did install on front wheel ramps, which was a bit tricky but only because down pipe to cat bolts were completely seized. I instead removed the stock cat plus down pipe together. The downstream O2 sensor came out with it too, just unplugged the wiring harness as a bit awkward to get to.

Once installed, significant difference in acceleration, very slight additional noise, but very slight. The car now feels like it should. You will definitely need CTS O2 spacer, so order and install together. O2 spacer has solved CEL and been driving full on for a couple of weeks now. Only grievance is that the supplied nuts for the turbo to cat bolts are a bit too tight fitting, I nearly stripped out a bolt and ended up using the stock nut, which was much easier. So Beware. I would also install the downpipe to the Cat out of the car, then thread it through from the top of the engine bay, it does fit with a bit of wiggling. Otherwise the bolts are a bitch to get to. Also the downpipe to transmission bracket doesn't line up, so I left it off. Would be better if it fit or came with a new connector. Still feels perfectly sturdy and no rattling or anything.