2001 buick century 3.1 v6

[Antwian30]

Hello everyone.. i was just wondering what are some of the symptoms of a bad cat converter..? I have been having some issues accelerating from stops, and especially going up hill!

Thanks for any help!

[HotZ28]

Could you explain the lack of power symptoms in a little more detail? Do you have any jerking under acceleration, or apparent misfire? Do you have any codes? Listed below are some typical codes that apply to catalyst efficiency. If no codes, take it to a muffler shop and have them perform a back pressure test.

DTC P0420 Catalyst System Low Efficiency
DTC P0421 Warm Up Catalyst Efficiency Below Threshold (Bank 1)
DTC P0422 Catalyst System Low Efficiency Bank 1
DTC P0423 Heated Catalyst Efficiency Below Threshold (Bank 1)
DTC P0424 Heated Catalyst Temperature Below Threshold (Bank 1)
DTC P0430 Catalyst System Low Efficiency Bank 2
DTC P0431 Warm Up Catalyst Efficiency Below Threshold (Bank 2)
DTC P0432 Catalyst System Low Efficiency Bank 2
DTC P0433 Heated Catalyst Efficiency Below Threshold (Bank 2)
DTC P0434 Heated Catalyst Temperature Below Threshold (Bank 2