What is the P0420 fault code and why does it matter? What is the reason for Catalytic Converter System efficiency below limit (Bank 1)? How do I fix the P0420 error code? What are the symptoms and causes of the P0420 fault?
What is the P0420 fault code? What does it all mean?
The catalytic converter’s task is to reduce harmful emissions from the exhaust (hydrocarbon (HC), carbon monoxide(CO), and nitrogenusoxide [NOx]) and convert them into harmless gases. The P0420 code means that the catalytic convert is not functioning efficiently, and the vehicle’s output of harmful pollutants is increasing.
Two oxygen sensors are installed in new vehicles. One at the catalytic converter’s outlet and one at its inlet. The first sensor adjusts the air-fuel mixture to ensure smooth engine operation. The second sensor measures the exhaust gases and controls the operation the catalytic converter. The ECU monitors the catalytic efficiency by comparing the oxygen sensors’ values. The ECU will generate the P0420 error code and turn on the engine malfunction lamp if there is an abnormal situation.
This is a sign that the catalytic conversion is not operating efficiently. The catalytic converters do not have wear parts and cannot be replaced. Many reasons can cause malfunctions.
Catalytic Converter Failure: What Are the Signs?
The converter may not have failed, but you might still be able to use the vehicle as normal. The converter does not pose any danger to the driver but can cause serious damage to other parts if it is not addressed promptly.
Don’t ignore any codes that are associated with P0420. The P0420 fault could have been triggered by P0300,P0302,P0302,P0303,P0304,P0305,P0306,P0307,P0308,P0307,P0308,P0307,P0307,P0308,P0308,P0308,P0174, and P0171 fault codes. These fault codes need to be addressed first.
- Flashing of the engine lamp malfunction indicator is the first indication that something is wrong.
- – The catalytic converter may be damaged, which can affect the vehicle’s acceleration and traction by restricting exhaust flow.
- – Vehicles may have a sulfurous odor similar to rotten eggs.
- – Vehicles start to burn more fuel and have a lower fuel economy.
Catalytic Converter Failure Causes
Fault code P0420 can occur for the following reasons.
- – The vehicle is refueled with leaded fuel, instead of unleaded.
- – The oxygen sensor is not working properly
- – Damaged or improperly connected outlet oxygen sensor wires (HO2S).
- – The engine coolant sensor is not functioning properly
- Cracked or damaged exhaust manifold/catalytic converter/muffler/exhaust pipe
- – Inefficient or defective catalytic converter
- – Ignition timing error
- – Fuel injector failure or high fuel pressure
- – Missing timing in cylinders
- – Engine burning oil
Catalytic Converter Failure Repair
The cost of replacing the oxygen sensor and catalytic converter is high. It is important to correctly diagnose the problem. Original parts must be used for replacement.
These are some suggestions for fixing and resolving P0420 fault codes:
- – First, check if there are other fault codes. They should be fixed.
- – Check the exhaust system for leaks and damage. Pay special attention to the exhaust system, including gaskets, tailpipes, and pre-catalytic convert. Repair any leaks and clean the code. To test it, drive around for a while.
- Compare the voltage signals for the first and the second oxygen sensors.
- Use a digital multimeter when the car is at normal operating temperatures to measure the voltage signal from the downstream oxygen sensor. The voltage signal should form a straight line, and produce a constant voltage value around 0.45V. The sensor should be straight and produce a constant voltage value of 0.45V. If it becomes wavy, it must be replaced. If the voltage fluctuates between 0.1V to 0.9V, this means that the catalyst is damaged and must be replaced.
- – Replace the catalytic convertor.
Suggestions
You can first check the exhaust temperatures before and afterwards the converter by using a laser thermometer. When the engine has been fully warmed up, the outlet temperature should be around 100 degrees Fahrenheit (309.92 Kelvin).
Owners of cars with P0420 fault codes make the most serious mistake and fail to immediately replace their oxygen sensor. It is crucial to get a proper diagnosis. You can avoid unnecessary changes and saving money by doing this.
It is highly recommended to use original parts if you have to replace the oxygen sensors or catalytic converter.
Vehicle manufacturers often offer extended warranties on emission-related parts. These parts can be extended even if the vehicle is not under warranty. These parts are often covered by a warranty of five years or more. Ask the manufacturer to address your issue.
