2014 TDI P2002 and P0401 help

[doogz]

Hey all, I recently purchased a 2014 Jetta SportWagen TDI 6 speed manual. I love the car.
After driving it about 1,000 miles since purchase I had P2002 and P0401 show up and soot on the tail pipe. No other issues associated with it, and I still get 40+ mpg highway. Is it still safe to drive?
I noticed looking at vwdieselinfo my car had the emissions modifications done at 97,007 miles and it is currently at 134,909 miles.
My question is has VW ever given any push back on replacing the DPF / Low pressure EGR filter yet again?
It says there is a warranty for 4 and a half years or 54,000 miles. Neither of which has happened yet.

 

[oilhammer]

You need a new DPF and EGR pipe. It is under warranty.

Read here:

CBEA/CJAA DPF info

Mods, please make this a sticky so I can easily point people here. When (not if) your CBEA or CJAA car flags the DTCs P2002, P0401, and sometimes P240F, and your car will have sooty tailpipes, YOUR DPF HAS FAILED. It is BROKEN. It cannot be cleaned. It will need to be replaced. This is the...

forums.tdiclub.com

 

[doogz]

Thank you! Will it hurt to drive the car until the dealership will look at it?

 

[oilhammer]

No, not in the short term.

 

[Stephan DPF]

Well, I had those codes while going on a trip from Montreal to Nova-Scotia. Just after a fill up at a very suspect gas station. I have a Blue Driver OBDII and I could monitor that it was doing its regen at about 300 km. The car had about 273 000 km. Well, no more warranty so it was either the scrap yard or try things. Well after visiting https://www.youtube.com/@ORileysAutos I suspected something was going on as stated by:

I decided to investigate.

I must say that in april 4 of this year 2023 I had a P2006 abd P2004 code that my mechanic told me to wait to the next revision.
I should have suspected something going on. But I attributed it to winter Diesel.

August P0401, P2002. I clear the code but make sure regen appens ( about 320km)
Clear code after each regen
I dicided to get a VCDS OBDII Reader. A necessity I realised when you drive a tdi. It took me a while to get used to the tool.
One shut of DPF cleaner additive. Makes the DPF within clearance.
P2002 again after a regen just about 300km later.
P2002 again after each regen.
I suspect injectors so I use injector cleaner (Archoil AR6400-D Diesel Fuel System Cleaner).
After 1 tank I get a lower about 0.1l/h idle consumption and a better running engine but still get p2002 after regen but lower soot (about 10g)
After second half tank I get P0401 with P2002.
2023-11-09
It stops regen. I use VCDS to investigate and I see that EGR cooler valve is blocked. (Using the basic setting EGR.... On Off get constant 500mg/str).
Looks like the additive blocked the EGR cooler filter and triggered the P0401.
Well, lets full it and do a standing regen. Good news now I get EGR cooler valve with a difference of 230 like expected. The engine really run differently on each On Off mode. Wow.
Soot measured as 3g now. So it look like a regen can clear the EGR cooler filter. My guess is that the additive made the soot with a lower ignition temperature, low enough to burn inside the cooler. (my daughter is a chemist and this make sense).
I do not make another regen now. My plan is to put more additive (adequate dose at the next full). I will do another similar measurement after another regen while driving (if it restart doing it....).
This gives me time to figure where is the real problem, MAF, intake leak, differential pressure sensor or an injector leak...

Take home message: Additive really makes a difference to clean soot. EGR cooler valve can be cleared during regen as the valve does open. Additive makes it easier as it lowers the ignition point of the soot.

I hope this can help.

 

[Stephan DPF]

Well, I did a slow adaptation of the DPF after about 500km as soot was building to 30g and pressure to 8mbar at iddle and the regen trigger was stuck at 100%. I verified first that the EGR cooler was effective using the On/Off basic setting on VCDS.
Regen happened just as I hit the highway and pressure and soot came down (2mbar, 3g). All parameter within range.
Well, P2002 came back after the next regen about 300km. One parameter is out of range(Blue driver gives a formated value of 1900 and it must be below 1600)
The car runs very nice. So I will keep you updated.

 

[Stephan DPF]

Well, so par so good. I decided to continue on Archoil AR6400-D Diesel Fuel System Cleaner after the last post on dec 18.
After 2 regens I was aware of, I get no more P2002.
at 281 623 km I get all green (https://1drv.ms/b/s!AvEyML-fvCyApZQCMW-pw9oin_T9Jw?e=ixosSa)
The car performs very well and I can perceive the EGR valve doing its thing in cold start. (No tailpipe smoke...)

 

[Stephan DPF]

Well on february 21 (285 360 km) I had P2004, P2006, P2008, with the P2002 along P0401 comming back, so I changed the intake manifold flap.
The car runs much better so I suspect this flap was not performing very well from the first CEL that simply when off before the next visit to my mechanic in february 2023.
So my guess is that all this Archoil AR6400 was working but the system was generating a lot of soot and was triggering P2002.
I have P2002 with P240F EGR Slow Response at 287 757 km. So my hope is that it will clean with time.
In fact as I write this the car has (at 289 167 km) P2002 as permanent and the P2040F disapeared and was permanent earlier.
Still resist to change the DPF as there is no soot at the exit pipe.
Finally, there is no more smell. I there was a leack from the intake manifold flap axe as I inspected the part.
I will order the AR6500 this time and put it in all fill.

 

[Stephan DPF]

Still have p2002 and P240F and now P0401 permanent.
I tried another shot of AUTOPROFI DPF Clean that I used at the first post.
This is more potent than Archoil AR6400. I drove 2 full tank with this cleaner and was still getting 6 mbar differential.
With the autoprofi DPF it when down to 2 mbar after only one regen.
Also regen are now at 284km.
I had a good result last year. I had those codes also. So I will drive to get below 1/4 of a tank and fill will AR6500.
Do another DPF clean and do a slow DPF adaptation.