DPF Light on

[Dread1977]

Hi,

could just be the G450 exhaust pressure sensor which is ~£50.

 

I would go with this first, very common fault depending on the age of your car.. mine failed and within a day my mates car of the same age had his fail... replaced myself in under half hour, got a mate with VCDS to do a forced regen and watched the soot levels drop to virtually 0... dont listen to anyone saying that your DPF is shot if its at 50 or 60% or more, mine was at 70 odd when I did the regen and it was fine... Skoda wont do it as there is a small chance it could get too hot and catch fire, but ive not known anyone to report this..

[Dread1977]

Just get it removed and a suitable remap to code it out.

Under normal driving you'll get better fuel consumption and never have this headache again.

If your handy with the spanners, do it yourself. You only have to remove the downpipe, use an angle grinder to cut it open and gut the innards, then weld it back up. Then £2-300 for a map.

 

Also you may want to think about doing this as I read an article saying that MOT failures will happen as a result of any tampering with the DPF if fitted as standard.. so thats taking a real chance these days with the (PC we will run your life for you brigade)

[Dread1977]

For the record I just noticed your Octy is the same year as mine so chances are its the G450 sensor as mine failed about 2 years ago... 

 

Quick run down of what I found out about the DPF and how it works below

 

You basically get 10 attempts to complete a regen before the car will go into limp mode, if it goes into limp mode sooner its because the sensor cant detect the levels of soot in the DPF so cant feed the right info back to the ECU and therefore the car has no idea how full it is, and to stop further issues goes into limp.

 

each time you start and drive and the car tries a regen this counts as 1 of your 10 attempts..

 

As soon as my car started doing this I looked on here and other forums and the G450 sensor was the main one talked about.. I changed it, took the car for a drive with VCDS plugged in and watched the levels drop down until it hit almost 0...

 

There are a lot of stories of people saying it cant be done above %50 which is utter crap, it can as i did!! there is none of this "adaptation" crap needed, I had been stuck in limp mode for days, replaced this sensor, did the drive and as soon as the soot level reached about 20% full power returned, all the lights went out and the car was fine.. I carried on driving like miss daisy in 4th at about 2500rpm to keep the temp in the exhaust high until it was all but clear.. never had a problem with DPF or regens since!!

[Dread1977]

Another 70 mph blast in 4th cleared it but I guess it's on its way out as I drove Aberdeen -Glasgow - Aberdeen at the weekend which should have kept it clear and it came on next day ! No danger of spending £1k , seen used ones for £120 on eBay and new ones for £450. Getting it cleaned out is an option , wait and see how long it takes to come on.

 

Also notice your speed here, you need to keep it below 50mph in 4th as its raises the temp in the exhaust more. if you leave VCDS plugged in and watch the temp you will see it rise a lot higher with less speed in a high gear at lower revs, the DPF clean under a forced regen stopped when I went too fast so it wont actually be clearing anything..

[Dread1977]

read this article...

 

On the PD170 the PDF sensor is under the engine cover, top left, covered in what looks like tin foil bolted to a bracket..

 

undo the bolt, unclip the pipes with some grips, little bit of fairly liquid on the new one and slide the pipes back on.. 

 

http://www.briskoda.net/forums/topic/237798-dpf-light-on-no-town-driving-pd170-vrs/?hl=%20gas%20%20pressure%20%20sensor

 

you may find you have revision A of the DPF sensor, and you want the latest on which may have changed but fairly sure its rev B.

[VrsMule]

Never experienced any reduction in power or mpg just the DPF light on (after idle revs increase) after last weeks blast been sweet as. Driven to Newcastle now going back up Sunday , seems to appear after a long run. Will see what happens. If it's on again I'll pull the codes.

[Rossvrs]

if the car does go into limp mode is there anyway to get it back out without the use of a computer ? 

[trundlenut]

if the car does go into limp mode is there anyway to get it back out without the use of a computer ?

No because you need to do a forced regent.

Sent from my Nexus 4 using Tapatalk

[VrsMule]

So after 2 months of DPF light free motoring it's back with avengeance was on , did the usual regen run, was off for 9 days then back on, did a run , off for 8 days , back on and cleared again today after a run !! How long will it stay off for !! I guess there is a finite number of times a regen run can be carried out ?

Andy

[silver1011]

Before you saw the light the DPF will have been regenerating (or at least attempting to) every 300-400 miles. It does this regardless of the level of soot deposits. 

 

So there is no limit on the number of regens, the limiting factor here is the amount of ash stored inside the DPF.

 

During each regen the DPF turns the soot to ash. The ash is stored inside the DPF for life. As the amount of ash increases it covers the internals of the DPF, the more of the internals that are covered the less efficient the DPF becomes. The less efficient it is then the more it needs to regen.

 

Have you read the codes yet?

 

A simple G450 sensor might do the trick. It is worth noting my G450 sensor was faulty and replaced, this didn't stop the DPF from failing only a few months later.

[VrsMule]

Ok , £650 for a DPF delete and re-map , sound about right ?

[silver1011]

Sounds high, although depends on the map.

 

If you just want the DPF sensors mapping out then you need a stage '0' map.

 

Having the DPF gutted and a stage '0' map is about £450 at Shark...

 

http://www.sharkperformance.co.uk/

 

Performance enhancing maps (stage 1 &2) bump up the price. 

[amk2vr6]

Or buy an MPPS cable from ebay and get a PD-Developments map and flash it yourself for under £100 all in

[VrsMule]

Please explain amk2vr6 ? I take it the DPf still needs removing ?

[amk2vr6]

Please explain amk2vr6 ? I take it the DPf still needs removing ?

 

Of course. You will either need to cut it out and reweld, or buy a delete pipe and fit.

 

However, it is still a cost effective way of doing it, and I am more than happy with the way it drives after remapping. It takes all of 10 minutes to flash too, and makes me wonder why I ever paid anyone in the past to do it for me. :(

 

In fact, if your ECU and software number is the same as mine, you can have the file at half price :P Saying that I would prefer to put you in touch with Lee at PD-Developments. Give him a call he is a very knowledgeable chap that is happy to help. I spent nearly an hour on the phone to him chewing his ear off haha.

 

He gave me two files to choose from. A conservative map around 195hp, and a stronger version supposedly around 210hp. I have confirmed values are increased in the latter by comparing the two files with Winols. And there is a definite improvement in performance between the two too.

[Huskoda]

A delete pipe would be stupid given its an instant obvious MOT fail. I think enough has already been said about DPF delete legality in that thread on the Fabia forum already

You may also find problems with declaring the delete to your insurer.

You can get your DPF cleaned out for less than you are looking at.

[amk2vr6]

A delete pipe would be stupid given its an instant obvious MOT fail. I think enough has already been said about DPF delete legality in that thread on the Fabia forum already

You may also find problems with declaring the delete to your insurer.

You can get your DPF cleaned out for less than you are looking at.

 

For it to happen again in future... Do it right, do it once.

 

Cut it open, gut it, and reweld. It wont fail seeing as its almost impossible to even see the DPF from anywhere due to its location on this car.

[trundlenut]

For it to happen again in future... Do it right, do it once.

Cut it open, gut it, and reweld. It wont fail seeing as its almost impossible to even see the DPF from anywhere due to its location on this car.

Do it once, until they change the mot to include a test for the dpf performance and then buy a new one or scrap the car

Sent from my Nexus 4 using Tapatalk

[amk2vr6]

Do it once, until they change the mot to include a test for the dpf performance and then buy a new one or scrap the car

Sent from my Nexus 4 using Tapatalk

 

Performance mods to fail too. Next up will be a quick dump of the ECU to see if its mapped. How about using non OEM parts as an MOT failure too?

 

[VrsMule]

Finally updated my VCDS , looks like the % value is 14.4 on block 075 and the value on 068 is 63 ? Will look again as swmbo is away in the Vrs so I can fix her A3 !! It's going through the auto re-gen process at the moment so no doubt the light will be on again. I'll update with better figs etc later. Do I need to look at blocks 068, 070 and 075 ?

Andy

[trundlenut]

You should have up to 4 values listed for each measuring block and they should have labels underneath them.

Sent from my Nexus 4 using Tapatalk

[VrsMule]

Particle filter load coefficient is at 30.2% (was 14.4% this morning)

Particle filter carbon mass is at 65.31

Carbon mass learned value is -6.8%

?

[trundlenut]

Mine is currently:

12:43:44 Group 068: Particle Filter (Exhaust Gas II)
  45.4 %  Particle Filter Load Coefficient
  37.0  Particle Filter Carbon Mass
  0.0 %  Carbon Mass Learned Value

Having done a spot of googling I found this which suggests you subtract the Carbon Mass Learned Value from the carbon mass, this gives a value of 58.51g for your car, which is sailing close to the 60g limit

[VrsMule]

So at 60g are we talking limp mode etc and the DPF requiring replacing ?

[trundlenut]

Or cleaning.