2002 Prius front exhaust assembly
I have a 2002 (first gen) Prius, which came with a long, one-piece front exhaust pipe assembly (part # 1741021261) consisting of two catalytic converters and a resonator. On my car, the second of the two cats is rotted out due to rust and leaking exhaust gas, although there is no code present. I would like to avoid buying the entire front assembly, which goes for $950, and would rather have a welding shop cut out the rotted cat and weld in an aftermarket cat. Does anyone know if it would be possible to do this? Would it cause a code? The problem is that the cat in question came with a special actuator mechanism and a hydrocarbon capture device, completely unique to this model, and I'm assuming it would be hard to find one of these used. Since the O2 sensor is forward of the cat in question, and there aren't any other sensors on this part, I'm assuming that the only issue would be ensuring that there is sufficient back-pressure, i.e., that there needs to be a second cat, but not necessarily one with the hydrocarbon capture function. Thanks y'all!
Art's Automotive dot com has an excellent article that inspired this idea. In that case, it was the forward of the two cats that needed to be cut out and replaced, which, fortunately for those guys, didn't require any special actuator or HC capture feature.