OBD P0420

OBD P0420

OBD P0420 obd p0420 ob2 code p0420 obd code p0420 obd code p420 obd code po420 obd ii code po420 obd po420 obd2 po420 code odb2 code p0420.


OBD P0420 code indicates that the Engine Control Module (ECM) has identified a decline in the efficiency of the catalytic converter on Bank 1. This could be attributed to a malfunctioning catalyst or potentially be a false alarm triggered by a defective O2 sensor. The engine control module (ECM) uses two O2 sensors, one in front, and one behind the catalytic converter to measure its efficiency. If the catalyst system efficiency is low, the P0420 code will be triggered.


Here are some of the most common reasons for the P0420 code:

  1. Faulty catalytic converter
  2. Faulty oxygen sensor
  3. Exhaust system leak
  4. Intake leak
  5. Incorrect placement of the catalytic converter

It may be due to a defective catalyst, but I have also seen many cases where the catalyst is new but is not an original OEM part. Some cheaper catalysts may not be efficient enough, and it could result in you needing to buy a brand-new catalyst from the manufacturer. I have also seen non-OEM catalytic converters that have been installed too far away from the engine on the exhaust pipe towards the last muffler. Because of this, the catalytic converter will not become hot enough, and it will trigger the P0420 trouble code. If the car’s air-fuel mixture is incorrect due to a faulty injector, high fuel pressure, faulty fuel system, or a damaged sensor, it may cause the catalytic converter not to function properly.


OBD P0420 reasons
OBD P0420 reasons

Here are the steps to troubleshoot the P0420 code:

OBD P0420 code troubleshoot
OBD P0420 code troubleshoot
  1. Scan the system using an OBD2 scan tool and check the error codes.
  2. Check the catalytic converter for faults. If it’s faulty, replace it.
  3. Check the oxygen sensor for faults. If it’s faulty, replace it.
  4. Check for an exhaust system leak. If there is a leak, repair it.
  5. Check for an intake leak. If there is a leak, repair it.
  6. If the catalytic converter is not an original OEM part, replace it with a new one from the manufacturer.

How to Protect Your Car

Here are some tips to protect your car from the P0420 code:

  1. Use the right fuel for your car.
  2. Maintain your car regularly. Regular maintenance includes changing the oil, replacing the air filter, and replacing the fuel filter.
  3. Drive your car regularly. If you don’t drive your car regularly, the catalytic converter may not become hot enough, and it will trigger the P0420 trouble code.
  4. That’s it! I hope this article helps you understand the OBD P0420 code better and how to protect your car from it
World Cup Points Team