What Is P0402

Diagnostic Trouble Code (DTC) P0402 stands for Exhaust Gas Recirculation “A” Flow Excessive Detected. It indicates that the powertrain control module (PCM) has detected excessive EGR. It is one of the generic diagnostic trouble codes in a number of makes and models that are related to the vehicle’s EGR.

How do I fix code P0402?

1. Replacing the stuck open EGR valve.
2. Replacing a broken catalyst in the exhaust.
3. Replacing an EGR temperature sensor or cleaning the carbon off of it to repair it if it registers too much of a temperature change.
4. Replacing the EGR backpressure control valve.

What does excessive flow mean?

Excessive flow means any infiltration of ground water or inflow of surface water into the Raymond or ‘South Bend wastewater systems that exceeds the accepted standard of good design, construction, and maintenance practices.