P2002 DPF Efficiency below threshold Issue - help!!

[Tom]

Hi Guys,

So I recently purchased my 2.0tdi Roc (170bhp) and only last week got it serviced at Volkswagen (inc new fuel filter). 130 miles after the service the EML came up, plugged in a fault reader and it came up below:



I've heard a few horror stories about the prices of DPF's and replacements etc, but just wanted some advice. I travel around 50-75 miles a day, all various traffic (town driving & motorway driving) so it does usually get a good run once a week or so, no short trips etc. I have some questions below which hopefully someone can help me with

1. Could any of this likely be related to a new fuel filter/the service carried out a week ago?

2. I reset the EML which went off, remained off for around 24 hours before re-appearing. I gave it a good motorway blast at 2500-3000rpm for a good 15 minutes but the light still came back on. Will I be causing any problems to the engine driving around with the EML on knowing that the dpf is the issue?

3. Would the best option be to replace the DPF, or just get it cleaned? I've seen you can buy those solutions which go into your fuel tank and supposedly clear the DPF - is it worthwhile or is it likely to cause more issues?

4. I've seen people do DPF deletes + remaps but understand this doesnt comply with MOT Regulations. Has anyone done this before and had any problems/is it worth the risk involved?

Any help/advice would be appreciated, thanks!

Tom

[Cuprabob]

I doubt very much it's anything to do with the fuel filter.

Although you are doing long trips, it's really how the previous owner used the car. Sensor failure is quite common on DPF so that may be worth.checking.

[Tom]

Thanks Bob, if it's a sensor failure would this just be a visual check? I deleted the error light again last night and going on a long motorway journey today to hopefully clear any carbon build up.

[Cuprabob]

You would check the sensor with VCDS. If the DPF is genuinely blocked and you can't get it to regen on a long journey, you'll need to take it to someone with VCDS to force a regen.

[Tom]

I'm probably being silly (apologies for the noob question) - what is meant by regen?? Is that just resetting the EML?

[Cuprabob]

Regen is regeneration of the DPF. Periodically, the ECU raises the exhaust temperature to burn off the soot particles trapped by the DPF. You can tell when it's happening as you get a sense of heat within the car, car idles faster and is a bit rougher. Also if you switch off during regen the radiator fans run on for 5 mins after switch off, to help dissipate the heat.

Explained here;

http://www.whatisadpf.com/dpf-regeneration" onclick="window.open(this.href);return false;

http://www.theaa.com/motoring_advice/fu ... lters.html" onclick="window.open(this.href);return false;

[Tom]

^ helps a lot, thanks again Bob. So far so good (I don't want to jinx things though!). Driven over 100 miles today and EML hasn't come back on - Ive been cruising the motorway in 5th gear at 2500-3000rpm so hopefully that has done the trick... I can only hope!

I will keep you updated if it comes back on, hopefully it doesn't = more money for car parts

Tom

[Tom]

it's back again EML came back on last night I'm gunna try the following:

- Tomorrow night I'm planning a regen - hopefully this will solve the issue.
- If that fails, I have some DPF Cleaner (you put it in your tank) as a second back up
- If that then fails, I'm going to try a new DPF sensor... after all, they are only £50 in comparison to £1500 for a new DPF!

I'll keep you updated with my progress and the outcome.

Tom

[Tom]

Just an update for anyone that may have the same issue in future! I couldn't do a regen as I plugged vagcom in and the carbon levels measured '0' (indicating it was just a sensor fault). So I replaced the sensor with a VW genuine part for £65.00. It's a slightly different part number as apparently these are more reliable/a newer version than those fitted as standard:



I fitted it on Thursday and have had no problem since (touch wood) so think it's done the job!!

Hopefully this helps anyone who may have the same problem in future

Tom

[Cuprabob]

Glad it turned out to be the sensor in the end.☺