How long do catalytic converters last?

[Akitadog]

I think it's pre 1974 here in CA.
Point being these older vehicles die off due crashes and just becoming too expensive to repair for their value. Unfortunately in this scenario, Jeeps have a high resale value... if they pass smog.

It's 74 and older are exempt.

 

[Jed57]

There are smog legal swaps you can do on a TJ. Mine is smog legal or it was. Where I live at in WA we don't have smog checks. Only in the big cities and surrounding areas. Rumor has it that they are going to stop doing smog tests but I don't see them doing that.

They’ll be like Pennsylvania, and other states I’m sure, they stop requiring things but still charge for them!

 

[OldButStillJeeping]

Ask around for a reputable exhaust shop. I found shop that said they would test my Cats for no charge. They drilled a hole in the pipe and tested the back pressure starting at the downstream cat. Mine was 3 LBS of back pressure. He said that would be enough to affect my performance. He cut that Cat out and noticed it was clogged with loose debris. We later found out a pre Cat had came apart and sent the pieces downstream. The plan was to replace the lower cat then re test the back flow pressure at the upper cats to see how they measured. I replaced the rear Cat and the pre cat closest to the firewall, which my guy said was common to fail. My LJ has 86k miles and runs great now.

Excellent. I'll look into this. Thank you.