My car si throwing code 67...catalyst system below efficiency threshold ...whats needs to be fixed??

 

not really sure, the shop manual should give you a list of things that it could possibly be, and from there its troubleshooting the system thats running insufficiently or replacing a part, dont have a manual at my house so i cant really help you.......

 

sounds like your converter may need to be replaced?
possibly a faulty o2 sensor?

you still have both o2s???

 

Clogged converter.