Has anyone had a computer code description come up on there car that reads "Catalyst Efficiency Below Threshold Usage" I don't have the code number for it. I had my catalytic converter checked and I replaced all the sparkplugs, coil packs and wires. In addition I recharged my K&N air filter and replaced the fuel filter. The car performs well with no problems.


Thanks!!

 

i had the same code on mine, had to replace the CAT.

 

Thanks for the information. Someone else had said it could be a faulty oxygen sensor.