Q: How to replace Catalytic Converter,Exhaust Pipe and Muffler in your Nissan 300ZX?A: To replace exhaust components, lift the vehicle and remove the catalytic converter shield. Disconnect brackets and bolts holding the front exhaust pipe, then remove it. Install with new gaskets and anti-seize compound. Secure the exhaust center tube, loosen the converter's mounting bolts, and remove it. Install with new gaskets and anti-seize compound. Remove the rear crossover bracket, heat shields, and U-bolt to disconnect the center tube. Install with new gaskets, anti-seize compound, and Nissan exhaust sealant kit 20720-N2225. For the muffler assembly, disconnect the U-bolt and bracket retaining bolts, then lower it from the vehicle. Install with new gaskets, anti-seize compound, and Nissan exhaust sealant kit 20720-N2225.