Engine Management Light

[Big Geoff]

Seat Leon Mk1 year 2003 1.6L

I have a problem with the engine management light permanently on. Got the code PO402 Gas Recirculation Flow (EGR) Excessive Detected.

Is there a common fault or a guide on the forum to find the cause.

Help appreciated.

 

[GlanzaV]

16786/P0402/001026 - Exhaust Gas Recirculation (EGR): Excessive Flow

Possible Symptoms

• Malfunction Indicator Light (MIL) ON
• Reduced Exhaust Gas Recirculation (EGR)
• Reduced Power Output/Engine running rough
• Increased Emissions

Possible Causes

• Exhaust Gas Recirculation (EGR) Valve stuck open/leaking/faulty
• Exhaust Gas Recirculation (EGR) System leaking/faulty
• Wiring and/or Connector(s) from/to Exhaust Gas Recirculation (EGR) Valve faulty

Possible Solutions

• Check/Clean Exhaust Gas Recirculation (EGR) System
• Check/Replace Exhaust Gas Recirculation (EGR) Valve
• Check Wiring and/or Connector(s) from/to Exhaust Gas Recirculation (EGR) Valve

 

[GlanzaV]

Looks like a faulty EGR valve - might be gunked up.

 

[Roohul]

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

Possible Solutions

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