Thought I'd start this as I'm a little confused over what is classed in the manual as a catalyst in the exhaust system of a manual D40 (not sure if it's fitted on the auto's) and I think some others are a little confused as well.
I'm no genius with cars and light commercials and more used to HGV's which don't tend to use dpf's.
As I said before it's labelled in the manual as a catalyst, being as it's a diesel it cannot be a catalytic converter as that's for petrol engines.
But it's clearly not a what I would call a proper dpf as it has no pre and post sensors.
It also can't be a poc (particle oxidation catalyst) as these are only a partial flow capture, where as when you look inside the one fitted on the D40 it's definitely a full flow filter with an internal make up similar to dpf's I've seen before.
Does this mean it's actually a depth particulate filter, which is like a halfway between a poc and a dpf, or is it a passive filter (a dpf that regenerates through normal use therefore not needing pre and post sensors to detect when the ecu needs to regenerate it).
The other question I have is why is an active dpf fitted to the automatic?
As I said before I'm no genius in cars but in the truck world the emissions are tested on the bench with a simulated load on the engine and if the engine meets regulation then it doesn't matter what gearbox is fitted as the engine has already been tested up to and beyond its maximum load capabilities in any scenario.
If this is the same with cars then why the dpf. The only other ideas I can come up with is using it as a way of obtaining a higher back pressure in the exhaust to aid in lowering engine revs quicker between gear changes to get a faster change within the box, or as a way of using the back pressure to force more waste gases through the egr when at a high load to create slightly less power as the gearbox can't cope with high torque situations. Again the second is highly unlikely or else there would be more failures than there has been and also they could reduce the power in these situations on the fuelling. But it is just a theory.
Either way these ideas are just that and using a dpf for these reasons seems like an expensive way of doing it.
Can someone with a little more info shed any light on this or am I just being daft and no one really cares :lol:
I'm no genius with cars and light commercials and more used to HGV's which don't tend to use dpf's.
As I said before it's labelled in the manual as a catalyst, being as it's a diesel it cannot be a catalytic converter as that's for petrol engines.
But it's clearly not a what I would call a proper dpf as it has no pre and post sensors.
It also can't be a poc (particle oxidation catalyst) as these are only a partial flow capture, where as when you look inside the one fitted on the D40 it's definitely a full flow filter with an internal make up similar to dpf's I've seen before.
Does this mean it's actually a depth particulate filter, which is like a halfway between a poc and a dpf, or is it a passive filter (a dpf that regenerates through normal use therefore not needing pre and post sensors to detect when the ecu needs to regenerate it).
The other question I have is why is an active dpf fitted to the automatic?
As I said before I'm no genius in cars but in the truck world the emissions are tested on the bench with a simulated load on the engine and if the engine meets regulation then it doesn't matter what gearbox is fitted as the engine has already been tested up to and beyond its maximum load capabilities in any scenario.
If this is the same with cars then why the dpf. The only other ideas I can come up with is using it as a way of obtaining a higher back pressure in the exhaust to aid in lowering engine revs quicker between gear changes to get a faster change within the box, or as a way of using the back pressure to force more waste gases through the egr when at a high load to create slightly less power as the gearbox can't cope with high torque situations. Again the second is highly unlikely or else there would be more failures than there has been and also they could reduce the power in these situations on the fuelling. But it is just a theory.
Either way these ideas are just that and using a dpf for these reasons seems like an expensive way of doing it.
Can someone with a little more info shed any light on this or am I just being daft and no one really cares :lol:
