Fault Code Scan & Reset Tools
Diagnostic World
Payment Options
Autel MD808 Pro Diagnostic World
Diagnostic World
Dash Warning ights

How To Fix: P0401 EGR Exhaust Gas Recirculation

This is a short guide on how to fix the P0401 fault code & check engine warning light. The P0401 fault code relates to the  EGR Exhaust Gas Recirculation insufficient detected message, which effectively means there is a problem with the EGR valve. The first image below is the check engine warning light that you will get, the image below that is the iCarsoft i908 kit diagnosing the EGR fault code P0401.
VW Golf GTI Check Engine Warning Light EGR P0401
P0401 iCarsoft i908 Diagnostic EGR Valve Fault Diagnostic World
A lot of people automatically that because they have received the P0401 fault code, it means the EGR value is broken or stuck, and needs to be replaced which can be pretty expensive. But did you know that the EGR value can be cleaned and put back to good working order by yourself?

If your willing to give it a go, and perhaps get your hands dirty you could well save yourself a few hundred £££ or $$$.

There are a number of points within the EGR valve system that can become clogged and restrict flow, and cleaning these areas can bring the EGR valve back to life.

Firstly you will need to let your engine cool before touching these parts. The exhaust gasses are very hot and can take some time for them to cool down completely.

Disconnect any electrical connections, and then disconnect the large vacuum hose, if this has a crimp style clamp you will need to throw it away and get a new one when refitting. Then you can remove the EGR valve itself.

There is a small test you can do by shaking the valve, if, when shaking, you hear a valve opening and closing, it means that it's still working and that the part can probably be cleaned and restored to working order, however if you do not hear any valve movement inside, we would still recommend you try to clean it in any case. What harm could you possibly do? 

When it comes to cleaning the EGR, follow these simple steps.

1. Remove the gasket, if the gasket looks in good condition you can re-use it. If it looks like it has seen better days you would be better off replacing it and buying a new one for when the EGR is re-installed.

2. Soaking the EGR valve, you should find a suitable bowl type container and fill it with carb cleaner and soak the EGR overnight.

3. Once you are happy that the EGR has had a good soak in carb cleaner, you need to clean the passages, surfaces & openings with brushes, you can use things like pipe cleaners, old toothbrushes etc. You should always use protective eye wear and chemical resistant gloves for this job.

4. Re-install your EGR valve and hopefully this will be an end to your problems. You can reset the fault codes and warning light by using one of our fault code readers.

The exampe shown in this write up was from a VW Golf, and we used the iCarsoft i908 to diagnose the EGR P0401 fault code. 
Latest Reviews...\r\n\r\nIan, Corby, UK\r\nGreat kit & great price\r\n\r\nRobert, Hull, UK\r\nSuper quick delivery, car now fixed\r\n\r\nDavid, Luton, UK\r\nCannot Fault a single thing\r\n\r\nSandy, Como, Italy\r\nEverything A OK A+++\r\n\r\nChris, Boston, USA\r\nFast delivery and good parts