Multi-code OBD2 diagnosis
Enter all the codes your scanner showed, not just the first one. We give you the overall severity, whether you can keep driving, the order in which to check them and how they relate to each other.
Summary
- Overall severity
- Medium
- Can I keep driving?
- Yes, but with caution
- Estimated cost
- $80 to $1,500
- Codes analyzed
- 1 of 1
The order below is the recommended one: first the codes that can cause the others. After each repair, clear the codes and check which ones come back.
Order of inspection
P0420 Catalyst System Efficiency Below Threshold (Bank 1) Medium
The P0420 code means the computer compared the upstream and downstream O2 sensor signals and decided the catalytic converter no longer stores oxygen the way it should. Before you replace the converter, rule out exhaust leaks, aging sensors and oil consumption, which are common causes of a P0420 on a healthy converter.