Toyota RAV4
P0421
The P0421 code indicates a "Warm Up Catalyst Efficiency Below Threshold (Bank 1)" issue in a 2019-present Toyota RAV4. This typically suggests a problem with the catalytic converter or the oxygen sensors.
3 SolutionsP-CodePowertrain
P
Error Code Type
Powertrain
Components
1 affected
Exhaust System
Symptoms
9 common
- •Check engine light illuminated
- •Reduced engine performance
- •Increased exhaust emissions
- +6 more
Most Affected Generations
2 generations
XA50
2
XA40
1
Top Affected Components
1 component
Exhaust System
3
Severity Levels
2 levels
medium
2
high
1
Quick Facts
3
Total Solutions
1
Affected Components
9
Common Symptoms
2
Generations
All Solutions
Showing 3 of 3 solutions for error code P0421 across all generations.