P0420
Catalyst System Efficiency Below Threshold (Bank 1)
Catalyst Efficiency DTC Codes
Catalyst efficiency below threshold and three-way catalyst OBD-II codes — context for de-cat downpipes and motorsport use.
About Catalyst codes
Catalyst codes (most famous: P0420 and P0430) trigger when the post-cat O2 sensor reading shows the catalyst isn't reducing emissions enough. After fitting a de-cat or sport cat on a track-only build, these need suppression.
All 37 codes in Catalyst
P0421
Warm Up Catalyst Efficiency Below Threshold (Bank 1)
P0422
Main Catalyst Efficiency Below Threshold (Bank 1)
P0423
Heated Catalyst Efficiency Below Threshold (Bank 1)
P0424
Heated Catalyst Temperature Below Threshold (Bank 1)
P0425
Catalyst Temperature Sensor (Bank 1)
P0426
Catalyst Temperature Sensor Range/Performance (Bank 1)
P0427
Catalyst Temperature Sensor Low (Bank 1)
P0428
Catalyst Temperature Sensor High (Bank 1)
P0429
Catalyst Heater Control Circuit
P0430
Catalyst System Efficiency Below Threshold (Bank 2)
P0431
Warm Up Catalyst Efficiency Below Threshold (Bank 2)
P0432
Main Catalyst Efficiency Below Threshold (Bank 2)
P0433
Heated Catalyst Efficiency Below Threshold (Bank 2)
P0434
Heated Catalyst Temperature Below Threshold (Bank 2)
P0435
Catalyst Temperature Sensor (Bank 2)
P0436
Catalyst Temperature Sensor Range/Performance (Bank 2)
P0437
Catalyst Temperature Sensor Low (Bank 2)
P0438
Catalyst Temperature Sensor High (Bank 2)
P0439
Catalyst Heater Control Circuit
P2096
Post Catalyst Fuel Trim Sys Too Lean Bank1
P2097
Post Catalyst Fuel Trim Sys Too Rich Bank1
P2098
Post Catalyst Fuel Trim Sys Too Lean Bank2
P2099
Post Catalyst Fuel Trim Sys Too Rich Bank2
P2423
HC Adsorption Catalyst Efficiency Below Threshold Bank1
P2424
HC Adsorption Catalyst Efficiency Below Threshold Bank2
P2567
Direct Ozone Reduction Catalyst Temp Sensor Circ
P2568
Direct Ozone Reduction Catalyst Temp Sensor Circ Range/Perf
P2569
Direct Ozone Reduction Catalyst Temp Sensor Circ Low
P2570
Direct Ozone Reduction Catalyst Temp Sensor Circ High
P2571
Direct Ozone Reduction Catalyst Temp Sensor Circ Interm/Erratic4
P2572
Direct Ozone Reduction Catalyst Deterioration Sensor Circ4
P2573
Direct Ozone Reduction Catalyst Deterioration Sensor Circ Range/Perf4
P2574
Direct Ozone Reduction Catalyst Deterioration Sensor Circ Low4
P2575
Direct Ozone Reduction Catalyst Deterioration Sensor Circ High4
P2576
Direct Ozone Reduction Catalyst Deterioration Sensor Circ Interm/Erratic
P2577
Direct Ozone Reduction Catalyst Efficiency Below Threshold