P0401 EGR insufficient flow-vw passat BKP

**DMitch16** · 08-05-2018,10:32 PM

Something like 15Nm for the flange iirc but best to check as overtightening will crush the rubber o ring gasket. The flange is less than £15 from the dealer and comes with an o ring gasket. Give the coolant temperature sensor a quick clean before you refit.

**DieselMonster** · 09-05-2018,06:25 PM

They say about 10nm to 15nm from various sources. I have ordered a aftermarket coolant flange, it should be good enough. Aftermarket one was £16, VW was asking for £32. I've also ordered the second O ring for the temp sensor. Will MAF cleaner be fine for the sensor when cleaning it?

**DMitch16** · 10-05-2018,02:00 PM

Originally Posted by DieselMonster

They say about 10nm to 15nm from various sources. I have ordered a aftermarket coolant flange, it should be good enough. Aftermarket one was £16, VW was asking for £32. I've also ordered the second O ring for the temp sensor. Will MAF cleaner be fine for the sensor when cleaning it?

Wow that's gone up - changed mine 4 or 5 years ago after a garage stuck it back on with silicone sealant to a new head they fitted (old one was cracked)!! Started leaking a whole tank of coolant in 20 miles. Wipe it clean with what ever you have as only surface deposits may affect its capability (the real magic happens inside so as long as it is not caked in limescale or rust it will be fine - unless faulty in which case might be worth it to pop a new one in while the pipe is off).

**DieselMonster** · 30-06-2018,05:47 PM

So I put everything back together and vcds is still showing egr insufficient flow. I went onto the engine control on vcds and clicked on egr to see the flow. The flow remained the same even though I reved it 2k. Check last two vcds pics below

VW Passat B6

Is the valve stuck closed?

**Gazwould** · 30-06-2018,06:11 PM

Blank and remap .

**DieselMonster** · 30-06-2018,06:26 PM

An option but I thought cooler engine temp was good for the engine.

**Gazwould** · 30-06-2018,07:37 PM

Dervs don't run hot , it's a case of do you want oxygen or less oxygen , less oxygen = incomplete combustion = soot .

**philipharmes** · 01-07-2018,09:55 AM

Originally Posted by DieselMonster

So I put everything back together and vcds is still showing egr insufficient flow. I went onto the engine control on vcds and clicked on egr to see the flow. The flow remained the same even though I reved it 2k. Check last two vcds pics below

VW Passat B6

Is the valve stuck closed?

Did you drive the car or was it stationary.

The EGR only opens at partial throttle & may not open at all ( part of the defeat software I would have thought ) while the car is stationary.

So the way it operates will also depend if youv'e had the software update or not.