Posts Tagged: P0420 after replacing catalytic converter

P0420 After Replacing Catalytic Converter? What to Check

Why Your P0420 Code Came Back After Installing a New Catalytic Converter Quick Summary Getting a P0420 after replacing the catalytic converter can be frustrating, especially after spending hundreds or even thousands of dollars on a new converter. In many cases, the new converter isn’t actually the problem. A P0420 code that returns after converter replacement because you didn’t fix the underlying cause that killed the previous converter. The most common causes of catalytic converter failure are: 1) Misfires due to an ignition problem (worn spark plugs or faulty ignition … Read More