My 2000 EX has a non-california legal cat in it. I live in california, so this is a problem. Luckily the smog shop didn't notice this time but I'd prefer to be on the straight and narrow with respect to emissions equipment.

There's a huge price difference between the OEM cat and even the most expensive california-legal aftermarket cat. Is the OEM cat at all worth it?

 

no, it isnt.

 

Magnaflow.

 

I got an OEM cat for my 1994 Civic for around $360 I think from one of the online Honda parts sites back in 2014. Dealer wanted $900. Original cat wasn't as effective after 408,000 miles. I've found that the high flow replacement cats don't last as long and weren't as effective after 80,00-100,000 miles.