MAGNAFLOW. Audi A4 B5 1998-2001 1.8T 4WD. Cat-Back System. 5 x 8 x 11in. muffler, 5 x 8 x 14in. resonator; 2.5in. tubing; 3.0in. polished stainless steel dual tips. Lifetime warranty, dyno tested and proven To make power, performance gains in horsepower and torque, great sound , has a smooth deep tone, easy to install, mandrel-bent. All Welded. Built To Last.