Akrapovic Downpipe Set w/o Cat (SS) for Mercedes W463 G63OP Optional partDownpipe Set w Cat (SS) was tested and developed together with Evolution Line (Titanium) system. For an enhanced exhaust tuning process, adding this sporty stainless steel downpipe set without catalytic converters takes the Evolution Line to greater levels. It is designed to provide the best sound optimization and increase performance due to the high flow downpipes offering less restricted airflow. The ECU will need to be remapped when