FWIW, the extra fuel injected does not ignite; it travels out the exhaust to help burn the soot out of the DPF. Ford and Dodge do this... GM has an extra injector downstream in the exhaust to do this.
One thought along this line: Us older types remember the failures the cropped up all over the place for 15 year or more when gas engines got emissions controls:
- cracked heads (induction hardend seats to allow no-lead gas)
- overheating (retarded timing to lower CO and NOx)
- piss poor power (lower CR to lower NOx)
- touchy carbs and lean burn (to lower HC)
- EGR's valves plugging up or freezing open
- air pumps failing
- catalytic converters crapping out and costing an arm and a leg to replace
So I'm gonna think this will improve with diesels over time. The present crop of light truck diesel emissions systems are
at least 5 years behind where the big rigs are. The 're-flashes' from the dealer are to improve the firmware managing these systems so that is evolving. Those of us with the present crop may have the 'guinea pig' systems of light truck emissions, like a 70's-80s' gas engined car.
The new electronics comm bus design is a big part of the problem with all cars/trucks. Sensors fail, but now their bus interface modules failures come into the picture too and the only way to presently manage that is to shotgun both the sensor and interface module. So a $150 sensor becomes a $500 sensor + interface module; the garages have no training or equipment to tell where the issues lie between the 2, even with some of the codes pointing to the likely cause. No difference there between diesel or gas; you would be fooling yourself to think otherwise because the gas version has the same comm bus system..... That is the only reason I paid an extra few $k for a 100k mile comprehensive warranty on the '16 Ram: the electronics. My '16 has 31 or 32 bus interface modules/local controllers in it that all communicate with each other!
And the bus connections get erratic or bus communications get out of sync. I get phantom rear air suspension alarms on rare occasion in the '16 and nothing is wrong; the alerts just appear then go away. Had that on an emission sensor last trip... showed up as active then became inactive. Sensor, interface, connection, bus comm failure? Impossible to say. How the electronics comm will be improved, if at all, I do not pretend to know.
With software comes flexibility, but software engineers are woefully short of knowledge on the failure modes of comm systems, and do an awful job of working around them. I've directly experienced some software engineers actually reacting with a blank stare and a "What do you mean the comm bus can go out them come back?" type of reply when you try to solve these problems!
