P0402: Exhaust Gas Recirculation Flow (EGR) Excessive Detected

What Does The P0402 Code Mean?

EGR stands for Exhaust Gas Recirculation. It is part of the vehicle emmissions system, and is used to reduce combustion temperature and pressure to control Oxides of Nitrogen.

There are generally three parts to the EGR system: the EGR valve, an actuator solenoid, and a differential pressure sensor (DPF). These things work together to deliver the correct amount of recirculation based on engine temperature, load, etc. The P0402 code means that OBD detected an excessive amount of EGR.

What Are The Symptoms Of The P0402 Code?

You may notice drivability problems such as the engine may surge off idle. There may also be other symptoms.

What Are The Potential Causes Of The P0402 Code?

A code P0402 most likely means one or more of the following has happened:

• The DPFE (differential pressure) sensor is faulty and needs to be replaced
• There is a blockage in the EGR (most likely carbon buildup)
• The EGR valve is faulty
• The EGR valve may not be opening due to a lack of vaccuum

How Can You Fix The P0402 Code?

With a P0402, it is common for people to replace the EGR valve, only to have the problem return. The most likely solution is to replace the DPFE sensor.

• Check the voltage at the DPFE sensor both at idle and when the EGR is open
• Replace the DPFE sensor

Related EGR codes: P0400, P0401, P0403, P0404, P0405, P0406, P0407, P0408, P0409

Recommended Parts

Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:

>>> Exhaust Back Pressure Sensor
>>> EGR Valve

Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!

Check This Video For Reference

Reference Sources

Diagnostic Trouble Code (DTC) Charts and Descriptions for P0402 – Page 67.