2000 E320 4matic plugged catalytic converter.
 

This morning my front cat,drivers side,got plugged while cruising on the hwy...so,I crawled home at 20mph and I am trying to figure out if I need a direct fit,or a independent muffler shop can put a generic one in place.I know that the rear ones are easy to replace with generic,however,never had to replaced the one in the front before...any input will be helpful,thanks.

Stick with an OE catalyst!

Have you had the exhaust back-pressure checked?

Has there been a recent air mass sensor failure?