General: V50/S40 DPF or FAP filter removal

[Stew]

Hello,
Not sure if this subject has already been covered but I thought I would post it in case it is of some use to people.
I have recently been having problems with my 2.0 TDI 2005 Volvo V50 going into limp mode. I did a diagnostic check and found it was showing a blocked DPF filter. I tried cleaning the filter with jet wash, detergent etc which worked for a while but it soon started to clog again as I use the car mainly around town. Decided that instead of replacing the filter I would try to remove it all together. Now I must point out before I go on that I am not some sort of electrical/electronic wizard, I just did a bit of reading and came up with a solution.

As you will probably be aware, you can’t just remove the DPF and begin driving again as the pressure sensor for the DPF will show a fault. To prevent this from happening you need to fool the ECU into thinking that the DPF is working fine. This was not as hard as I first thought. The sensor for the DPF (attached to the battery housing) is fairly simple. It has two pressure pipes which are feed from either side of the filter, an electrical socket with a 5 volt live, an earth and an output wire which sends a voltage to the ecu. I worked out that if the ECU receives a voltage of approximately 0.35 volts it believes that the filter is working fine. I therefore cut the three wires feeding the sensor and fitted a 5k Cermet potentiometer (see below). These can be found at Maplin or eBay for under £1.50p

http://www.maplin.co.uk/Module.aspx?ModuleNo=2202

These simply allow you to adjust the output voltage from 5volts down to zero in very fine increments. I then soldered the earth wire to the earth connection of the potentiometer, the 5v cable and output cable to the remaining connections on the potentiometer. Once that was done it was just a simple case of setting the output voltage to the desired reading which is approximately .35 of a volt and clearing any fault codes from the ECU. I also took the DPF filter off the car and removed the carbon insert with a large drill.

The engine has run for a few weeks now with no pending or current faults on the ECU.

Like I said at the start, I am no technical guru but I would say that anyone who can use a soldering iron, multimeter and a large drill could do this and save a fortune on replacing DPF’s or having your ECU remapped.

Hope this is of help to someone.

Cheers,

Stew

[Bryan271]

Very intresting indeed......Did you find any difference in power or fuel economy??

[fenton_jd]

How much soot comes out the back now?

[Jonnieb2009]

Well done on finding a bypass solution to dPF issues but I have a few comments (just my opnion for what its worth):-

The filter must have been put there for a good reason?

Whilst that is a short term 'bypass/fix' will removing the DPF not have long term effects on the car/peformance issues?

rgds
J

[Stew]

I have not noticed any difference in power, economy or soot coming from the exhaust. The car appears unaffected. There are plenty of companies on the internet that a remapping ECU’s to effectively erase the DPF from the system. I haven’t heard any horror stories after extensive searching on the internet so I can’t see it having any effect on the engine.

Cheers

Stew

[Bill_56]

Interesting, Stew.

I have to ask... have you notified your insurance company? If so, how did they react?

You don't have to notify them of course, as long as you never make a claim they'll be none the wiser, and they'll be happy to take the premiums.

But many companies have a policy that, if the driver fails to notify them of a modification, then the policy is invalid and they wouldn't pay out in the event of an accident (it wouldn't matter whether the modification contributed to the accident).

[s40s]

That is what I am going to do as soon as damn thing starts playing up. Stew here just told everybody how to save nearly £1k and all you can think is your insurance company. Here are few suggestions to make things a bit tidier: If Stew could use multimeter and find out exact resistance of potentiometer I could use resistor instead ,which is smaller and can be hidden inside a wire with heat shrink ( http://www.rapidonline.com/Cables-Co...kw/Heat+Shrink ) in which case insurance company would have to split wires to find it. Also what size drill bit have you used? Did you made one hole in the center or few of them?
Few things from my own research:
Peugeot owners have privilege to remove filters for a long time. If you will be nice on the forum they will provide hacked soft for ecu. After flash whole DPF is shut means no additive to fill, no rising oil, no fuel waste on regeneration almost like back in a good old days. For the final thought did anyone actually calculated benefit that DPF provides and waste associated with regeneration. If a car regenerates, burns more fuel all the time because of short journeys I guess it might be less wasteful and ecological without it.
Sorry for broken English.

[nallen132]

Will the car still pass it MOT on emissions?

[7050man]

Originally Posted by nallen132

Will the car still pass it MOT on emissions?

No, it will probably fail the particulate test.

[faffi]

Getting rid of the DPF will only to the engine good. Should give more power and a little reduction in consumption. I would most certainly not retain the DPF once the warranty was out and a replacement was needed. Thanks to Stew for sharing his findings