Can a bad (or old) cat converter ruin a motor overtime?

[Leonard 3.8L]

Someone told me it can, but I don't believe it unless someone has been there that can tell me. Mine is about 10 years old. At this point, should it be replaced?

[CDNFB]

Re: Can a bad (or old) cat converter ruin a motor overtime?

Depends on what is meant by "bad"

A converter that is old but structurally intact presents no problems to the longevity of your engine. When it gets to the point that the catalytic reaction is no longer effective (cause the materials are worn out) the 3rd O2 sensor (OBDII) will sense this and set a DTC. Even at this point you could drive the car for as long as you want with no problem, except that the SES light would always be on (could be annoying)

Converters that are structurally compromized can cause lots of problems like Carbon monoxide poisoning and fires (from holes, cracks, splits) to exhaust system blockage (from pieces of the core migrating into and along the pipes to the muffler).

Blocked converters and/or exhaust systems can cause engines to run poorly, get bad gas mileage, and no power, and can overheat exhaust valves and damage them if left uncorrected for extended periods of time.