Thanks, M.B.Doc !

RE - "Only 1986 calif. cars have traps from factory."

I'm confused about the above comment after the mention of 86-87 model years and the oxidation catalyst modifications.
Does this mean 86 Calif cars were not allowed the modification ?
Also, do these catalysts have a limited lifespan and wear out ? Just so I can figure out, based on when the modifications were allowed (starting which year after the failures ?) so I can figure in on possible replacement cost when looking at one of these cars for possible purchase.

Thanks for your help.

VA300SD ('81)