How To Clean EGR Valve (Also a Fix For P0401)

Clean EGR Valve

A common question I see come up in the forums is 'How to clean a EGR Valve?'. So i thought I would be nice to create a quick reference laying out the steps to ensure a through clean. This is also a known fix for fault code P0401 Insufficient Flow.

The EGR valve removal procedure varies a lot between cars and I cannot list every way to remove the EGR Valve so I will assume that you have access to the internal part of the EGR Valve. Also it isn't a necessity to have diagnostic kit or a vacuum pump for you car, I will list extra steps you can take if you have access to these, or even a cheap OBD Scanner. See here OBD Scanner Review or here ELM327 OBD Ssanner. You will however require some carburettor or air intake/EGR cleaner which is available a all decent part stores or from here, All Trade Direct 1X Wynns Egr3 Exhaust Gas Recirculation 3 Cleaner Air Inlet Diesel Egr Erg 23379 

Step 1: Remove any loose or excessive carbon build up with a flat bladed
           screw driver.

Step 2: Spray cleaning solution into EGR Valve. Leave to soak for 20mins.

Step 3: If you EGR Valve is a Vacuum operate one and you have a vacuum 
           pump, connect it to the pipe fitting on the EGR Valve and pull a 
           vacuum to open to EGR Valve. If you have an Electronic EGR Valve and
           a diagnostic tool capable of operating the EGR Valve, with the EGR 
           Valve connected to the wiring harness, open the valve with the 
           diagnostic tool.

Step 4: Using a soft bristled tooth brush, scrub the EGR Valve, spray further 
           cleaner into valve if needed. Once all traces of carbon are removed, 
           using a lint free cloth dry the EGR Valve.

Step 5: Disconnect vacuum pump or diagnostic tools.

Step 6: Refit the EGR Valve.

Step 7: If you have access to a OBD Scanner clear the diagnostic fault codes.
            If not you may need to take your vehicle to a repair shop or garage to 
           have the codes cleared.

Step 8: Road test the car to make sure the fault doesn't return.

If you car is suffering from fault code P0401 you may be suffering from some of these causes.

• Broken or corroded wiring for the EGR System.
• Broken or Split vacuum pipe
• Faulty Differential Pressure sensor for the EGR (DPFE)
• Faulty EGR Valve