Cat & O2 sensor life expectancy?

[turn6]

Car is an original '86 Calif car with 123K mi that i've owned since ~55K mi. Do 'cats' generally degrade over time? What about O2 sensors? Since i perform my own maintenance i've never replaced either. I've been thinking about Fabspeed's euro pre-muffler but am curious what others have experienced. My oem muffler has been gutted. I'm currently using an older Automotion/Weltmeister/Dinan chip with a modified airbox with stock paper filter. Only other mod is the brown wire running parallel with the main wire harness into the dme is unplugged supposedly mimicking a '49st car. Tia.

Ps. i think it was Steve W. who originally posted about making a Cal car like a 49st...if you're reading this was there ever any follow-up to that thread. Thanks again.

[Jim Smolka]

O2 life varies. Depends on junk that gets on the sensor tip.

I have seen many high mileage sensors pass the factory test for new sensors. It is just one of those things that unless you have the big $$$ for a factory test station, just cheaper to replace the unit.

[Doug Zielke]

If your cat is like mine ( on a shelf, asleep in the basement) it will last forever.