Q: Tengo una hyundai santa fe el código que me dice es p0421 q pieza puede ser ? Por el muffle huele raro

Hello, thank you for writing in. The code P0421 means the exhaust system is detecting an issue with the fumes being to rich. This can happen when the spark plugs are worn and cause the fuel not to burn correctly, when the catalytic converter has failed and needs to be replaced, or when the oxygen sensor that reads the fumes has failed and needs to be replaced. All three of these components need to be inspected and tested. The smell you are noticing is likely due to excess fuel in the exhaust fumes, or from the catalytic converter not doing its job. For more help with the issue, contact our service department to schedule an appointment.