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OBDII Code List

P0420 CHEVROLET - Catalyst System Low Efficiency 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
  • Powertrain Control Module (PCM)
What does this mean?
OBDII Code P0420 Chevrolet - Catalyst System Low Efficiency Bank 1 -

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Posted and Edit by 08-15-2016