Hi,
My Doblo has just failed it's CT (French equivalent of MOT) as engine management light is on and the error code is P0401 (exhaust gas recirculation flow insufficient detected). The light has been on for over 12 months and the vehicle runs the same as ever, this has happened before when the light came and stayed on for months and then went off on its own. I've bought a cheapo OBD11 reader my question is can I just simply delete the code to turn the light off or should I do something more and of so what? Hope someone can give me some advice, thanks in advance.

Delete the code and see how long it takes to come back on.

P0401 is a standard code which signals that the temperature doesn't change when the EGR should be active. It points to a not working EGR.
The code will come on again until you fix the EGR (or its triggering).

Which way your EGR works depends on the engine you have.
If it works via vacuum check the vacuum that the EGR works with.
If it works electrically check the cables and plugs.

Good luck

When the eml is on, do you get a bleep sound every 5 minutes or so.

Thanks all I bought a diagnostic tester and it cleared the code but the light came back on after about 3 weeks. Still haven't noticed any difference in running or performance so I will clear the code again just before it goes back in for its retest. Thanks

If it's a diesel, cleaning the EGR valve and pipe might fix it.

401 is lack of exhaust gasses so the egr is not opening enough, cleaning wont help, either the motor is lazy or any open far enough.
New egr is the only way forward.

Mjsroofing said:

401 is lack of exhaust gasses so the egr is not opening enough, cleaning wont help, either the motor is lazy or any open far enough.
New egr is the only way forward.

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I had the same code on my VW Caddy the EGR of which was vacuum driven. More than one garage (VW dealers included) couldn't find a fix for years. (They managed to pass the MOT-equivalent though but the code was already back when i picked my van up after.) I found the solution myself at the end: The muff for the vacuum pipe on the vacuum pump was just a tiny bit leaky and that not even always. A bit of acrylic grease and a a wire to tighten the tube fixed the problem.
The new tube for 30 and two hours work for 160 had been completely for nothing, and i'd been quite lucky not having ordered the new EGR valve for 250 and/or the new tandem pump for 650.

Presumably your EGR valve is driven electrically (which i don't know), and cleaning it will not be the worst idea but you should search for the reason why it doesn't work properly if you don't want to blindly invest in unneccessary parts.

Good luck