2012-15. Catalytic cnvrtr lock nut. A solid metal or plastic bLock with a threaded hole in the center which is used to tighten or adjust the Exhaust System Resonator. Catalytic Converter Nut. Exhaust Flange Nut. Exhaust Muffler Nut. Exhaust Pipe Nut. Part cannot be reused/reinstalled. Catalytic cnvrtr. Converter. Converter and Amplifier. Exhaust Flange. Filter. Hanger. Hexagon collar s. Muffler. Muffler and Amplifier. Second Converter.