p0420
Moderate
Maserati · Sedans & Sports Cars
Catalyst System Efficiency Below Threshold (Bank 1)
Quick Answer
Error code P0420 on your Maserati Sedans & Sports Cars means: Catalyst System Efficiency Below Threshold (Bank 1). This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Diagnose with OBD-II scanner for related codes
2
Inspect catalytic converter for physical damage
3
Check oxygen sensors before and after catalyst
4
Look for exhaust leaks
5
Monitor fuel pressure and trim values
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Catalytic converter
Oxygen sensor
Gasket seal kit
Related Error Codes