Dpf DIY

brownie 25

Registered User
Hi all,I've tried a search with no luck.Is there any how too or the likes on removal of the dpf mine is blocked so I'm going down the route of gutting the dpf and then getting it mapped,I know the basics on taking the the dpf out of the car,is the dpf and cat in the same housing?any help much appreciated
 

Cyrix

Registered User
It is combined on the PD170, removal of the complete brick can be done without cutting it open quite easily.

Here is the one from my PD170 Avant
image1.JPG

Here is a bit of advice you may find helpful - In order to smash to insides out you will need to separate the DPF from from the downpipe. This will probably cause some issues as the bolts will be corroded, I would be very surprised if yours are not. I ended up cutting the studs off the DPF and drilling out the remains, then using three new bolts to re-attach the DPF to the downpipe. If I was doing it again I would probably leave the DPF bolted to the downpipe and have the brick removed that way. You will need the car pretty high in the air in order to remove the DPF/downpipe as one unit.
 

brownie 25

Registered User
When ye say combined is the cat and dpf in the same housing or are they actually one unit that needs to be removed?cyrx how would you get it out if you were to leave it bolted together ?
 

Cyrix

Registered User
You would need to cut the side of the DPF open, remove the brick and have it rewelded.
 

brownie 25

Registered User
Am I right I thinking that the dpf is on the back section of the housing and not the turbo side ? I don't want to remove part of the cat without knowing or is there a noticeable difference in them.
 

brownie 25

Registered User
That would be too easy lol, main reason is to save 150 quid but I like to Do anything I can when it comes to things like this plus I have everything I need to do the job so I might as well use them
 

brownie 25

Registered User
Cheers for the offer mate but in in Ireland,but any advice you can give would be great.out of curiosity what do you charge for the while job
 

brownie 25

Registered User
Cheers paul I got that,so do you have advice on gutting the dpf, do I need to cut it open or can it be done through the exit side of the housing
 

brownie 25

Registered User
If I remove the dpf does it have to be mapped straight away or could I drive away for a while,I'm afraid dy driving it the way it is it will do damage to the turbo or worse, so hopeing to do it this weekend along with the manafold flap motor but won't be able to get it mapped for a week or so.its has eml and glow plug light flashing now and there isn't enough power to pull the socks off a dead man.i
 

Cyrix

Registered User
Should be ok, if you have access to VCDS reset the DPF ash mass value to zero to keep any regeneration at bay until you have it mapped out correctly.
 

brownie 25

Registered User
Cheers for that cyrex I'll be starting it later today so all goin we'll be back in the car in the morning
 

brownie 25

Registered User
So all went well so far,only prob I have is I think I might have taken the cat aswell.i didn't cut it open I managed to get the down pipe off fairly easy so went that way I broke out bit by bit assuming I would come to the end of the dpf and then see the cat but not such luck it was one complete piece so the housing is empty now OOPS.all lights are off now and its got full power back again.
can anyone tell me why it needs to be mapped,also there is very little smoke from exhausts
 

desertstorm

Moderator
Staff member
Moderator
VCDS Map User
It needs to be mapped to switch the DPF functionality off. You will get an engine management light sooner or later as the ECU will be expecting the pressure in the DPF to increase, if it doesn't it will probably assume there is an issue with the pressure sensor and throw a fault code which may put the car in limp mode.
There won't be a lot of smoke the standard mapping on a car with a DPF runs pretty lean otherwise the car would need to regenerate a lot more often.

Karl.
 

brownie 25

Registered User
Cheers Karl so is it safe to drive it for a few days before its mapped? Any idea about the cat I read somewhere that there was a space between the.cat and dpf but from what I could see it was the same honey comb Block the whole way trough
 

Cyrix

Registered User
The one on mine was the same, one block. Mine is mapped and produces next to no smoke, the only difference is it smells a bit more.

It will be ok for a few days (mine was) just get it mapped out sooner rather than later.
 

brownie 25

Registered User
WOW :)
Car now mapped and ##ck does it move, the lad that done it said it was approx 200 bhp, it feels like more and pulls mental in every gear and sounds good too.only thing is the smell of fumes inside the car now and then I had a look at the flexie joint when it was off, the wire stuff around the outside was broken but the inner part looked ok,where else could the fumes be coming from.This is something I need to fix ASAP as the kids are in the car every day
 

Cyrix

Registered User
Pretty common issue with gutted DPF's

Check the seal between the bonnet and bulkhead, and tailgate in case they are worn. Most people just select recirculate when stationary.
 

SDHA4SLine

Registered User
Wondering why the pro's don't gut the DPF your way rather than cut it open and weld. What's the crack anyone, why not do this instead cut and weld?

By this I mean what's the disadvantage of removing without cut and weld ?
 

Cyrix

Registered User
If the DPF and Cat are two seperate bricks within the housing then cutting and welding allows you to remove the DPF brick and leave the cat. The downside is the failure point you have introduced, I guess it depends on how good the person welding the filter back up is.

Most cars don't have clear to the DPF is any case, the one on the A4 is pretty handy as you can get access to the brick quite easily through the outlet of the filter.
 
Regarding removing the dpf only and leaving the , does that not cause issues down the line with cat becoming an ineffective and unnecessary (as presumably environmental concerns are trumped by power making potential ;) ) further restriction in the exhaust system ?
 

brownie 25

Registered User
All was going so well, car is still driving fine but doesn't seem to have the same power it had after being mapped I know people say you use't to it but it is deffinetly not as powerful as it was two days ago,there's no lights on either. Any ideas ?
 

Paul @ Unit 9 Remaps

Registered User
id question the map.

cutting it open is loads better in my opinion. you can visually see that you have removed everything and all the insulation. id hate to think that there was still abit left still inside' id hate to be doing the job twice. also the reason the other members above have said. theres alot of dpf's that you cant really get into proper due to the angle of the inlet and outlet of the units. why risk' cut it open and make sure you remove everything as thats the point and you have a bigger area to work with and its also quicker than trying to knock it through. and another note you can get away with out trying to remove the sensors. so can be a pain and try to strip threads and so on.
 

brownie 25

Registered User
Hi Paul,I will waiting at the door on Monday morning for him to check it out.He told my that he uses some company in Germany for the mapping, he sends them some sort of info about the car what I don't know and they send back the new info to map it,is there any truth in that or do ye write the map there and then?
 

Paul @ Unit 9 Remaps

Registered User
Yeah there's truth in that, but the maps are only as good as the company doing them, are the reputable' if there's a consultancy of people having problems I would be worried, it could be a one of in fairness you need to know what he is going to say and it can happen I suppose.
 

Gaz170

Active Member
VCDS Map User
i would definitely side with Paul here cutting is best way to make sure completely empty
After doing my own dpf which i cut open there is a fibre padding around the core of the dpf pipe if yours has the same did you completely empty it of everything ?
if some padding left inside it will come loose an block the pipe
 

brownie 25

Registered User
Ya hopefully its something simple,he is meant to be the go to guy for this sort of stuff,he doesn't just do mapping his place at any one time has 15/20 high spec cars in there,and there about 10 different laptops and computers on trolleys around the place so by the looks of it he knows what he doing.
 

brownie 25

Registered User
Not at all cool out lol, but he better fuc**n fix it,I'm hooked on flooring it away from the lights when there's a Fella beside me thinking look at your man driving daddy's station wagon
 

SDHA4SLine

Registered User
Glad I asked now as I was seriously considering doing this myself. does the cat usually go also or is it let in place.

Brownie25 sorry for hijacking your thread, hope you don't mind me asking these questions
 

brownie 25

Registered User
Hijack away pall the more info the better,If your handy with a spanner do it your self but I'll be honest it's can be daunting, but at the end of the day it's only nuts n bolts.i saved 150 euro doing it myself a half decent socket set will do most of the work
 
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