Catalytic cnvrtr flange. Left.6.0 LITER. Right.6.0 LITER. A stamped or cast metal plate along with bolts and sometimes nuts holds the flared end of an Exhaust pipe to the ball end of an Exhaust pipe, Exhaust manifold or Exhaust adapter found in turbocharged applications. Connecting Flange for an Exhaust System Catalytic Converter. Included with: Catalytic Converter.