BMW 3 Series
P0420
The P0420 code indicates that the catalytic converter efficiency is below the threshold on a BMW 3 Series E90/E91 (2005-2012). This typically suggests an issue with the catalytic converter itself or the oxygen sensors.
60 SolutionsP-CodePowertrain
P
Error Code Type
Powertrain
Symptoms
10 common
- •Check engine light illuminated
- •Poor fuel economy
- •Decreased engine performance
- +7 more
Most Affected Generations
1 generation
E90
60
Severity Levels
1 level
medium
60
Quick Facts
309
Total Solutions
0
Affected Components
10
Common Symptoms
1
Generations
All Solutions
Showing 60 of 309 solutions for error code P0420 across all generations.