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Discussion Starter #1
So here's the latest in a number of dramas with my 93 ttid. (front and rear springs decided to snap a couple of weeks ago).

Easter weekend drove from London to leeds to Birmingham and back to london. On the last leg of journey the lovely Limited Performance sign pops up and into limp mode we go. Luckily could get up to 60/70 mph so got ourselves and little one home.

Checked car, tail pipes covered in soot. All else fine, no other check engine light etc. Over the course of the week limited performance came and went randomly. Hmmm. EGR got a good clean, hoses checked for leaks, maf and map cleaned. LP still came and went.

So thought maybe dpf. In the 6 months I've had the car I've never had to clean the tail pipe of soot. They've been squeaky clean. For them to now be covered in soot made me think there were some serious issues.

Nice day today so cracked open tool box and pulled dpf rear pipe to see what was going down. Low and behold the dpf has self destructed. The centre of the ceramic core was crumbling apart and partially melted. I can only hypothesise but regen caused over heating maybe as the core was fully blocked? There was no crappy additive in the diesel so can't think why, maybe someone on the forum can shed some light.

Anyway with nothing to lose I pulled out a hard core masonry drill bit and chisels went about breaking down what I could of this pile of junk. Might as well let the engine breath. Managed to get 4 holes about 75 percent of the way through at 12, 3,6 and 9 o'clock. Chiseled away what I could of the rear of the ceramic as this was crumbling anyway.

Turned engine over and blew out all the crap and ash. Battery unplugged and ecu reset. I'm about to take her for a spin and see how she goes.

BTW this was done with DPF still attached at the front end. Its an easy job. 1 clamp bolt and 2 for the bracket that support the dpf. Then wiggle out.

Will post back with an update later...

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Discussion Starter #2
20 mile trip @ steady 70mph , no codes or limited performance, much better acceleration especially at 40 to 80mph. Better still mpg hit 55... I've never managed more than 50 in the time I've had the car. So far so good. Would recommend to anyone having trouble but not wanting to fork out hundreds for a delete and remap. From what I've read the sensor set up on the z19 engines allows dpf gutting without throwing any codes. Let's see what happens on next regen... I'm thinking it will further melt down the ceramic core which I'm more than happy about.

Scanned with opcom too which picked up a dpf code that my other reader wasn't picking up. Cleared it. Worth the investment.
 

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Interesting, I was thinking about this myself. How easy is it to disconnect the other end of the dpf to remove it fully? I have read about cleaning them out with brick acid or a high pressure hose
 

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Would have been easy to get off, just 3 very rusty nuts that connect the flexi exhaust section. I didn't want to risk in case they crumbled on me. Loads of wd40 and wire brush and you should be fine.

Worth a try with soak in brick cleaner overnight followed by jet wash. I would have done that had mine not failed. Only watch out might be getting it on the catalyst at the front of the dpf. Not sure if this would damage it/dissolve the metals. You could always dip it to three quarters of the way up - I think the catalyst is the first 4 inches or so. You can tell where it ends as there's a change in the shape of the dpf casing (it dips inward)
 

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what will happen when a regen is attempted I wonder ?
Doesn't the ECU dump fuel down the pipe to intitiate a regen ?, what will happen to that fuel ?

I''ll gut mine if it gives trouble but I'd imagine it'd need to be deleted in the ECU software as well.
 

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Discussion Starter #6
Fuel is pumped in to react with the catalyst and heat up the dpf to burn the soot. I've not removed the catalyst. It should just heat up as normal during any regeneration. From what I've read about the process on the z19dtr the ecu uses load and duration data to determine when to regen, other systems use pressure sensors (which would detect a gutted dpf) so not worried about the need for remapping ecu. Done 300 miles trouble free. Economy has been transformed, even in crawling traffic with auto box I'm still managing over 50mpg. Less load on engine = fewer regenerations = better economy
 

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If they are both in the same pipe where does the DPF end and the cat start? I wouldn't want to drill straight through into the cat by mistake
 

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Discussion Starter #8
See my earlier post. Cat is first few inches. When looking at the dpf outer casing you'll see where it changes shape. There's a gap between the cat and where the dpf starts. Unless you have a 2ft+ drill bit you won't go through it :)
 

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So far still running sweet, great economy, no fault codes or limited performance. Giving a regular thrashing to push to the limit and try to get a fault but absolutely fine.... Covered over 4k miles since gutting. Only gripe is black tail pipes! Need to clean every weekend but can live with that...
 

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the differential pressure sensor is in the bulkhead so yes if it was fully gutted it would throw a code

it would of broke down/melted because in most cases it was at the end of its useful life or a cheap aftermarket fitted previously

what you have done is great in the way it has released the pressure within the limits to what the car sees as normal due to the rest blocked. it will indeed regen as normal and the chances off further issues are limited for quite some time due to the hole sizes,

on the other hand and by no means am i condemning what you have done.....its a game of Russian roulette drill one to many holes and your fcuk'd as it will detect a pressure difference, but at this stage its worth ago as the dpf is fcuk,d anyway so not losing anything really

the best way to do this is to drill (not on hammer) 3 or 4 10mm holes around the centre of the dpf core at approx. 10-15mm apart which can be seen to be done on other manufactures

you may see slight puff of smoke during a regen but hey ho who cares !!
 

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@kez you may be right. still not 100% clear on how the dpf system on the z19 works. WIS states the pressure sensor is only used for diagnostic purposes and to prevent a manual regeneration being carried out when the dpf is too full. From the pics you'll see I drilled 4 holes approx 2cm in diameter. I also chiseled out the back end of the dpf so essentially opening up all the passages removing restriction in flow a bit like gutting it, although the core being present will give some pressure. If anyone has gutted completely without a remap please post back on whether you're getting codes / limp mode.
 

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Well done Raj.

Love this kind of post. Just shows to me car repair and innovation is not yet dead, although is in severe decline!.
Not many could even think about what you achieved and it could help many others in the same position, providing they read the cautionary parameters regarding how much honeycomb to remove.

Great.
 

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http://garagewire.co.uk/news/government-investigates-dpf-removal-ahead-of-crackdown/
In the year since he did it , I think all as been well , he has not reported back with any kind of failure since . Very cleaver what raj did and he knew when to stop drilling .
DOT have been slow to catch up on this. be interesting to see what happens when and if cars/vans start failing on dpf removal and how exactly will they check. al MOT stations will require new kit possibly a software update to as they have the measuring kit already i guess.....
 

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Pushing the mustard some ........ But if ya bought a dpf from ... XYZ Breakers....... & Spend a goodly amount of time, disembowling it ...... So ya has a huge expance with a probe in there ....... What then ? .... Just thinkin' :D
 

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I was experiencing ups and downs in my TTID power output & lot of weird regens over the last two months, so I did the same thing on my DPF this weekend and drilled some partial holes in it. I think I went some 1-2cm deep with a 8mm drill and might have gone over board with the hole count :D ended up with 10 holes or so in the end. The engine is definitely much more responsive as many others have reported and pulls way better in all gears. However I would not suggest drilling so many holes - the exhaust now has a slightly deeper tone to it and during a regen on a highway @ below 2000 revs it felt like driving a broken muffler with a hole in it. Had to keep revs above 2500 not do go mental. At least I now always know when the regens are happening lol :D

I've read plenty of reports also in Alfa forums how 159 has the same DPF and amongst them this partial drilling is quite popular. They've even gone as far as drilling the dpf thoroughly and for some time this one guy was selling obd dongles that reset the dpf countdown so it wasnt necessary to get a remap which deleted the regens.

However nobody has written anything about loud regens. Hope it's no biggie :)

Follow-up edit: I had the dpf to exhaust clamp loose so the loud noise came from there. Two regens since that, now it only regens at certain distance intervals - every 640kms (which was also confirmed by raj). Now I just reset my trip computer every time and it's easy to plan my regens so they're not interrupted.
 
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