P0420 code in your vehicle indicates the issue of catalyst system efficiency below threshold fix. The catalytic converter's function is to degrade dangerous pollutants produced during the combustion cycle. By filtering exhaust gases through fine platinum and gold meshes, the catalyst can lower emissions.
What is Code P0420?
P0420 code indicates a catalytic converter problem. By filtering exhaust gases through fine meshes of platinum and gold, the catalyst can reduce emissions.
Two oxygen sensors are installed in the catalytic converter. One oxygen sensor is located ahead of the catalyst, while the other is behind it (downstream).
If the upstream oxygen sensor is functioning properly, it should oscillate between the warm-up to the operating temperature of the vehicle and closed-loop operation.
If the lower lambda probe is appropriate and the catalytic converter is not malfunctioning, its reading should remain stable. When the oxygen sensor reads the same value, the catalytic converter is not functioning normally. If the downstream oxygen sensor voltage drops and fluctuates, indicating that the oxygen level is too high, the Powertrain Control Module (PCM) will store a P0420 fault code and illuminate the warning light.
Common Causes of Code P0420
A leaking or damaged muffler. The exhaust manifold is broken or leaking. The drain hose is damaged or leaking.
Engine pass. Catalytic converter oil contamination Catalytic converter failure (most common).
The engine coolant temperature sensor is faulty. The wiring for the oxygen sensor is faulty. Examine the engine light to see if it is illuminated. A variety of factors can cause the Check Engine light to illuminate.
To read the code and determine the root cause of the problem, the mechanic will need to use a diagnostic tool. After the vehicle warms up, there is no power. The engine will perform poorly and may not offer adequate acceleration power. The maximum speed of the vehicle is 30-40 miles per hour.
The exhaust reeked of rotten eggs. This odor is caused by insufficient oxygen in the catalytic converter, which can result in high levels of sulfur in the fuel tank, resulting in an odor in the exhaust system.
How does a mechanic identify a P0420 error code?
To retrieve trouble codes stored in the PCM, use an OBD-II scanner.
Data from downstream (rear) oxygen sensors is displayed in real-time. The voltage reading from the downstream oxygen sensor should be consistent. Check that the downstream (rear) oxygen sensor is working properly.
Determine whether any other codes are causing DTC P0420. As needed, repair misfiring, ignition problems, and/or fuel system issues. Examine the rear oxygen sensor for any signs of damage or excessive wear. View freeze frame data to see if the downstream (rear) oxygen sensor is functioning properly.
If the catalytic converter is faulty, look for PCM updates. A PCM update will be required after replacing the catalytic converter.
The most common error is replacing the oxygen sensor before the diagnostic process is finished. If the P0420 fault code is caused by another component, replacing the oxygen sensor will not resolve the issue.
