What are the chances of a cat converter going bad at 80k miles? My car has been driving sluggish lately, the exhaust seems to running hotter than usual - more loud clicking sound, when the car is let cool down. Any way to check and rule out that possibility?

 

I guess the best way would be to do what I'm about to have to do today, pull the cat off and inspect.

 

Aku's suggestion is best. You could check with a non-contact pyrometer aiming at the pipes before and after to check temps if you can find one. Does AZ offer free or cheap emmisions tests?

 

You might want to call either your local Nissan dealership or Nissan USA and see what the Warranty on the emissions system is. It might still be under Warranty.