The bypass pipe I have bought has a small tube on the front to install the pressure sensor and a 'nut' welded over a hole to screw in the temp sensor.
AFAIK we are not allowed to post links to adverts but a search of ebay italy 'DPF bypass' will find them
That looks up to the task for sure.
When I went to my 'MOT' they plugged a unit into the ODB port which I assume (amongst other things) stops a regen occurring during the MOT. Probably H&S doesn't like the exhaust going to 600°C whilst the man is under the car meddling ;p
Chris, I have no idea where you get the estimates of how often a DPF will regen from.
Based on my understanding of the dpf system. The pressure rises in front of the filter, this is interpretted as a blocked filter and a regeneration is started to burn off the blockage.
My DPF (which is in good condition, in as much as a DPF can be) does a regen every 300-400km.
How do you know the condition of your DPF ? What characteristics of the dpf have made you declare it's condition to be 'good' ? Have you connected it to an examiner or AlfaOBD or similar and read out the clogging value ?. What miles are on the dpf ? what sort of driving conditions do your trips normally comprise of ? Those are the things which affect the condition of a dpf. A dpf with 30k miles could be completely blocked, if the car has only seen short and infrequent town trips. A car used daily for 200 miles on the motorway will probably still have a working dpf after 70k miles. But, these are only assumptions.
Secondly, a regen every 300-400km is a sure sign of severe blockage. When I picked my car up in January from a place 400 miles away I drove it back along the motorway all the way, stopping halfway for snack. It didn't regen at all. After a few weeks my work pattern changed (I work standby and callouts now) and sometimes my daily mileage might be less than 20 miles aroundtown. I could guarantee that almost every trip on the motorway (every week or so) would initiate a regen cycle. And it's been like that every since, more or less. I have no doubt that when I got the car the DPF was going to be fine as long as I did a lot of motorway running and the exhaust stayed pretty hot, but it was blocked enough for it to be a problem as soon as that driving pattern changed.
Knowing what we do about how a regen cycle contaminates the oil (as mentioned in the video I posted ), consider that your car is going to regen at least 100 times between oil changes and dump diesel into your oil every time. This must affect the service interval if not the ability of that oil to lubricate effectively.
By fitting the bypass pipe you are going to be letting the engine breathe well, and there should be no regens taking place to contaminate your oil. Like I said before though, please fit it and see if it regens. I'm pretty certain that it won't, and you'll immediately notice much improved performance and economy. If, after 500 - 1000 miles it hasn't regenerated, you will have some great data for us all won't you
I read your thread on drilling it out and it seems reasonable if you don't mind destroying the unit.
But it's already destroyed and has no value as anything but a pipe connecting two halves of my exhaust together, while working as a power sapping and fuel consuming blockage.
What I have is, as Monty Python would say, "An ex-DPF"
Drilling it out doesn't damage the outer casing and only about 20-30% of the core was removed in total, mostly from the central area.
I genuinely believe that a good dpf and regeneration method is valuable and important. But I think a bad one is useless to the point of actually bringing about another problem - if a blocked dpf causes higher fuel consumption by 10%, as mine did....what is worse for the environment, a blocked dpf causing high fuel consumption or a more efficient system with fewer emmissions (with possibly only slightly more soot)
Diesel dpf technology is still relatively new in domestic cars, it will not be a perfect technology for a while yet
At least one of the tuner companies (with a good rep) does this and then remaps.
I know of at least one saying and doing a similar thing for bypass pipes.
From DPF Removal Alfa 159, Brera & GT + EGR Valve £300
If you just bypass the DPF and do not remap the car after, and by remap we mean the program that makes your car move, run and stop, the ECU will continue to try and regenerate and you will just be pumping in the same rich fuel which will not burn properly and you will be wasting money on expensive fuel AND your car WILL smoke like hell!
"the ECU will continue to try and regenerate"
I have not found that to be the case. Since drilling out my DPF I have done over 400km (greater than the figure you are seeing between regens) and haven't had a regen, and I am certain it is because the % clogging figure is very low.
The same people also say this
Each DPF can only regenerate so many times, then it just stops. When the filter reaches perhaps 40% full the car is in limp home mode and you loose all power. The DPF will need to be replaced.
"when the filter reaches perhaps 40% full" - is that so ? Mine was way beyond 40% (measured using Alfa ODB) and it has never entered a limp home mode. (It has always driven like there was something stuck in the exhaust though
)Maybe that was changed in the 2008 - models following complaints ? Maybe 40% is just a suitably scary value though too.
If the way to sell disinfectant is to make people scared of germs, what do you need to do to sell a remap ?
At this point we need to look into the mind of the engineer who decides what features to add into the software and think about why a regen is necessary and wonder, if my car tries to regen when it isn't even blocked, what is the purpose of that ? Why waste fuel and contaminate the oil for no good reason ? What is the payback from a pointless regen ?
By triggering a regen by mileage you don't take into consideration the fact that the mileage might take the form of dpf clogging town miles, or dpf cleaning motorway miles. By triggering a regen by a time counter you also can't tell how the car has been used. And if you did use mileage or time as the significant variables, why waste money on a pressure sensor in the first place ? Before DPF's there were no pressure sensors in the exhaust (not so far back in the system).
The point of the DPF is to capture soot while you drive around town to keep down city pollution levels, and when you get out onto the open road regeneration should take place if it is required
, just as long as it's not in the city.
I will tell you if my car tries to regen, but I have some faith in the hypothesis that the trigger to a regen is high pressure in the DPF case, not mileage or time. Bearing in mind there is a variable in the ECU called 'Duration of last regeneration'. If the regeneration routine is a predetermined, preprogrammed routine, why store the duration of the last regeneration for recovery later ?
it must be the case that either there are different regen programmes, or, the regen is controlled in some other way. Pressure ?