What can do to fix code p0421?

Answer 1

Code P0421 indicates that the warm-up catalytic converter efficiency is below the threshold. To fix this issue, first, check for any exhaust leaks or damaged components in the exhaust system, as these can affect sensor readings. Next, inspect the oxygen sensors and catalytic converter for proper functionality and replace them if necessary. Lastly, ensure that the engine is running optimally, as misfires or fuel system issues can also contribute to this code.