The CTS B9 A4 / A5 2.0T test pipe is the premier test pipe for your Audi A4 / A5 2.0T. Our test pipe is designed to seamlessly fit in place of your restrictive stock catalytic converter, which is situated immediately after the turbocharger. Our test pipe features 3" stainless steel piping, smooth mandrel bends, one 02 sensor bung with an option for a second. Substantial power gains, improved exhaust flow and a more throaty sound are the main benefits from installing our test pipe. Upon inspection you will notice a flare which is nearly 4", this flare then tapers to 3" and is designed to allow for optimal flow as the exhaust gas transitions from the turbocharger to the test pipe. In addition to being one of the best bang for the buck performance upgrades for A4 owners our test pipe is also very attractive piece. Each 3" test pipe is mandrel bent, hand tig welded. Do you need an additional 02 bung for data logging? Well that's no problem! Tig welding additional 02 bungs can be done for an additional charge. \n \nProduct Details: \n- T304 stainless steel construction \n- Mandrel bent stainless steel \n- Fully tig welded design \n- Install hardware included \n- Throaty sound \n- Great power upgrade \n \nTo remove the CEL that will occur, proper tuning software must be used. CTS Turbo recommends choosing a High Flow Cat for the sake of our environment! \n \nUse of stage 2 software upgrade is strongly recommended.