I have no knowledge of how the DPF on tractors work. I have a Cummins that utilizes the DPF technology. I have read one way to bypass the regen cycle allowing the removal of the DPF is the use of SIMS. Basically either 110 ohm or 330 ohm resistors plugged into the sensors along the exhaust system. Fools the computer that a regen is not required thus allowing the removal of the emission crap.
Perhaps something similar would work on these new tier 4 engines.
I've read much about DPF, regen, etc. Prior to a couple of years ago, there were several companies selling "DPF delete" kits for USA diesel pickups. These consisted of a reprogrammed on board computer and a bypass pipe. The EPA came down hard on them, fining them $500K (IIRC) and requiring they buy back product sold (doubt if they got many takers). Other makers of DPF delete kits took note and ceased sales.
In Europe, diesel cars have suffered from poor performance and reduced mileage due to clogged DPFs, especially in urban, low speed driving. The diesel needs to be operated at a high enough power setting to provide the heat needed to burn off the particulate in the DPF. This heat may be provided by post combustion fuel injection (spraying diesel fuel into the exhaust ahead of the DPF - - makes heat, lowers mileage (this is the system used on the B3350).
Some enterprising souls in EU have simply drilled a few holes laterally through the DPF, thus "unclogging" the exhaust and assuring that the delta-P (pressure differential) sensor doesn't send the dreaded "regen-NOW or we shut down to limp mode" message to the computer.
So why not simply drill a few holes through the DPF and weld a SS patch at each end to cover them? Well, the DPF filter on the B3350 costs $2,500 and is under warranty longer than the tractor proper (I think 3 years). They would doubtless void any warranty on anything if it's messed with.
BTW, from what I can tell, there are 3 temperature probes on the DPF. There is also at least one pressure differential sensor. Some computers, besides monitoring temp and pressure conditions, also have a timer to call for a regen after a given amount of operation, hours or mileage. Further, the fuel injection timing is retarded - this to raise exhaust temperatures for more efficient DPF operation - unfortunately the retarded injection also reduces power. So to take advantage of the power and added fuel efficiency of bypassing the DPF, it is necessary to reprogram the computer to re-time injection also.
Unfortunately, to do it right does not seem so simple as just replacing probes with resistors and installing a bypass pipe. Even without the EPA breathing heavily down our necks, the market segment is too small to encourage the proper DPF delete kits with computer remapping that we saw for over the road diesels.
IMO, another case of our EPA running amuck. Consider the multiple millions of jet-a (essentially diesel fuel) that is burned by airliners with no regard for smog or particulate emissions whatsoever. Balance that against a little tractor that might see a couple of hours of use a week.
bumper