Review on Walker Exhaust Ultra EPA 15823 - High-performance Direct Fit Catalytic Converter with Advanced Emission Control Technology by Justin Ritter

Good fit, familiar high quality Walker design. First loosen the O2 sensor with penetrating oil and twist it both ways. Mine had more resistance halfway through and the sensor threads had to be cleaned with needle files before threading easily into the new transducer. No studs, unlike the original block, so you need 6 bolts (shank diameter 10mm, thread 1.5mm, shank length 35mm or 40mm) to use with the old nuts. Mine were rust free so they put anti-seize paste on the screw threads. When in doubt, buy new nuts and make your life easier next time. Gaskets were also ordered but they came separately and came later. It's best to buy them from a parts store if you're on a schedule. Be careful with heat shields, the edges are sharp. Anti-seize only on the O2 thread, can kill the sensor on the tip. A drop of penetrating oil on hangers will help. Simple work, fast delivery, convincing price. The truck is a CA model, but there is no inspection here. No CEL after switching.