OBD2 Automotive Error Code P0402: How to Fix It

Q: Can I drive with error code P0402?

You can drive short distances with P0402, but it should be fixed soon as it can cause poor fuel economy, rough idling, and increased emissions. Extended driving may lead to engine damage.

Q: What causes P0402 error code?

P0402 is typically caused by a stuck-open EGR valve, damaged vacuum lines, carbon buildup in EGR passages, or a faulty EGR position sensor allowing too much exhaust gas recirculation.

Q: How much does it cost to fix P0402?

DIY cleaning costs $10-30 for cleaning supplies. Professional diagnosis and cleaning ranges $100-200, while EGR valve replacement can cost $200-500 depending on the vehicle.

Q: Will P0402 clear itself?

P0402 will not clear itself as it indicates a mechanical problem with the EGR system. The underlying issue must be fixed before the code will stay cleared.

Q: How do I prevent P0402 from returning?

Prevent P0402 by using quality fuel, changing air filters regularly, performing regular maintenance, and occasionally driving at highway speeds to help burn off carbon deposits in the EGR system.

Abstract

Error code P0402 indicates that your vehicle's exhaust gas recirculation (EGR) system is flowing too much exhaust back into the engine. This can cause rough idling, poor acceleration, and increased emissions, but is typically fixable with proper diagnosis and cleaning.