Posts Tagged: P0420 code
Most Common Causes of Catalytic Converter Failure
Top Reasons Catalytic Converters Go Bad Quick Summary The most common causes of catalytic converter failure are • Engine misfires — Misfires cause incomplete combustion that dumps unburned fuel into the exhaust, causing the catalytic converter to foul, overheat, and melt. • Rich fuel mixtures — Leaking fuel injectors or rich fuel mixtures cause extra fuel to enter the exhaust and damage the catalytic converter. • Oil or coolant contamination — Oil burning, internal oil, or coolant leaks can coat the precious metals inside the catalytic converter, rendering them inoperative. … Read More
Why Oxygen Sensors Rarely Cause P0420 or P0430 Codes
Understanding the Relationship Between the O2 Sensors and a P0420 or P0430 Code Quick summary An oxygen sensor rarely causes a P0420 or P0430. That’s because the engine computer needs a working oxygen sensor to even test catalytic converter efficiency. A P0420 or P0430 means the converter is no longer storing oxygen properly, or there are underlying issues like exhaust leaks, fuel trim problems, or engine conditions that slowly killed the converter. Understanding how the computer uses the oxygen sensor data makes diagnosing P0420 and P0430 far more accurate and … Read More
P0420 Code Causes and Fixes
How to Properly Diagnose a P0420 Code Quick Summary The P0420 code indicates that your vehicle’s catalytic converter is not reducing exhaust emissions as efficiently as the engine computer expects. In most cases, the code means the catalytic converter has failed and must be replaced. However, in some cases, the cause can be due to an exhaust leak that’s skewing the results from the oxygen sensors. Many owners consult the Internet and believe that replacing the oxygen sensors will solve the problem, but that rarely works. If the oxygen sensors … Read More