For Shop Owners

P0420 HONDA - Catalyst System Efficiency Below Threshold Bank 1

Repair Importance Level: 2/3
Repair Difficulty Level: 2/3 What does this mean?

Possible causes

  • Three way catalyst converter Bank 1
  • Exhaust tube
  • Intake air leaks
  • Fuel injectors may be faulty
  • Fuel injector leaks
  • Spark plugs may be faulty
  • Improper ignition timing
  • Engine Control Module (ECM)
What does this mean?
OBDII Code P0420 Honda - Catalyst System Efficiency Below Threshold Bank 1 - kvjournal.ru

P0420 HONDA Information for specific Honda models

Need more help?

Do you need more help with the P0420 Honda code? Ask a question to our users or find an automotive repair shop near you to help fix the OBDII code