My engine check light came on and it said "Catalyst Threshold Efficiency Low." on 2005 Acura TL

What does this mean? Someone please help!

1 answer
one of your catts is going bad did it say bank1 or 2 and per catt or post catt. it means you o2 sensors are not seeing enough difference between pre o2 and post 02 but u need to figure out if its an 02 issue or catt issue.rec seeing a mech that knows these cars for proper diag