P1420: Catalyst Temperature Sensor Failure

MediumPowertrainCatalytic Converter

What does P1420 mean?

P1420 is a diagnostic trouble code indicating "Catalyst Temperature Sensor Failure". The catalytic converter in your exhaust system is not converting harmful gases as efficiently as required. This affects emissions and may indicate the converter is failing or there is an upstream issue.

Common causes

  • Aging catalytic converter
  • Engine misfire damaging the converter
  • Oil or coolant entering the exhaust
  • Faulty downstream O2 sensor giving false reading

What should you do?

Schedule a diagnostic appointment at your earliest convenience. The vehicle is generally safe to drive short distances, but the underlying issue should be addressed to prevent it from worsening.

Get a diagnosis for YOUR car

Code P1420 can mean different things depending on your vehicle. TorqueBot gives you a diagnosis specific to your make, model, and year.

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Related codes

P1421Catalyst Damage
P1314Misfire Rate Catalyst Damage Fault - Bank 2
P1313Misfire Rate Catalyst Damage Fault - Bank 1
P0439Catalyst Heater Control Circuit (Bank 2)