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[STEMO]

90 odd miles in the last three days - running lovely, quiet, powerful, drives beautifully. I've learnt a few things, and having never worked on one of these before, I'm still chalking it up as an overall result

Another diesel convert
Opti next.

[JamesV6CDX]

Still a few niggles

Every now and again (each 50 miles or so) the engine ECU is initiating a passive DPF regeneration. This is where, for about ten minutes, it increases the fuelling, to “burn off” soot inside the DPF. This increases the heat in the exhaust and the engine and while as an occasional thing isn’t harmful, it wouldn’t do any good to let it keep happening. It also kills MPG.

In my simple mind, I don’t understand why it’s trying to do a passive regen. It can’t be sensing the DPF internals are getting full, when there’s none in there 

[STEMO]

Still a few niggles

Every now and again (each 50 miles or so) the engine ECU is initiating a passive DPF regeneration. This is where, for about ten minutes, it increases the fuelling, to “burn off” soot inside the DPF. This increases the heat in the exhaust and the engine and while as an occasional thing isn’t harmful, it wouldn’t do any good to let it keep happening. It also kills MPG.

In my simple mind, I don’t understand why it’s trying to do a passive regen. It can’t be sensing the DPF internals are getting full, when there’s none in there 

Mine  does one about every 300 miles, lasts about 10 mins, as you say. The idle speed creeps up from about 850 to 950, that's how I can tell and know not to switch off.
It's a pressure reading from the dpf that sets it off, so could the ecu be getting a signal from somewhere?

[JamesV6CDX]

Still a few niggles

Every now and again (each 50 miles or so) the engine ECU is initiating a passive DPF regeneration. This is where, for about ten minutes, it increases the fuelling, to “burn off” soot inside the DPF. This increases the heat in the exhaust and the engine and while as an occasional thing isn’t harmful, it wouldn’t do any good to let it keep happening. It also kills MPG.

In my simple mind, I don’t understand why it’s trying to do a passive regen. It can’t be sensing the DPF internals are getting full, when there’s none in there 

Mine  does one about every 300 miles, lasts about 10 mins, as you say. The idle speed creeps up from about 850 to 950, that's how I can tell and know not to switch off.
It's a pressure reading from the dpf that sets it off, so could the ecu be getting a signal from somewhere?

I think it works on sensing the pressure differential between the exhaust gasses before and then after the DPF. But in my simple head, with the DPF being empty, there shouldn’t be enough of a pressure difference for it to assume any blockage, which makes me wonder why it’s trying to regenerate itself so much 

This is all academic anyway as I’d have to fit a DPF anyway if I ever sold the car. Now the engine is in good order I might just do that anyway. It’s unlikely to clog now, and would prevent any issues at MOT time

[Raeturbo]

Has it got a cat fitted too? If so maybe it’s something to do with that

[STEMO]

Still a few niggles

Every now and again (each 50 miles or so) the engine ECU is initiating a passive DPF regeneration. This is where, for about ten minutes, it increases the fuelling, to “burn off” soot inside the DPF. This increases the heat in the exhaust and the engine and while as an occasional thing isn’t harmful, it wouldn’t do any good to let it keep happening. It also kills MPG.

In my simple mind, I don’t understand why it’s trying to do a passive regen. It can’t be sensing the DPF internals are getting full, when there’s none in there 

Mine  does one about every 300 miles, lasts about 10 mins, as you say. The idle speed creeps up from about 850 to 950, that's how I can tell and know not to switch off.
It's a pressure reading from the dpf that sets it off, so could the ecu be getting a signal from somewhere?

I think it works on sensing the pressure differential between the exhaust gasses before and then after the DPF. But in my simple head, with the DPF being empty, there shouldn’t be enough of a pressure difference for it to assume any blockage, which makes me wonder why it’s trying to regenerate itself so much 

This is all academic anyway as I’d have to fit a DPF anyway if I ever sold the car. Now the engine is in good order I might just do that anyway. It’s unlikely to clog now, and would prevent any issues at MOT time

You did delete the dpf from the car?

[Raeturbo]

Good point

[JamesV6CDX]

Still a few niggles

Every now and again (each 50 miles or so) the engine ECU is initiating a passive DPF regeneration. This is where, for about ten minutes, it increases the fuelling, to “burn off” soot inside the DPF. This increases the heat in the exhaust and the engine and while as an occasional thing isn’t harmful, it wouldn’t do any good to let it keep happening. It also kills MPG.

In my simple mind, I don’t understand why it’s trying to do a passive regen. It can’t be sensing the DPF internals are getting full, when there’s none in there 

Mine  does one about every 300 miles, lasts about 10 mins, as you say. The idle speed creeps up from about 850 to 950, that's how I can tell and know not to switch off.
It's a pressure reading from the dpf that sets it off, so could the ecu be getting a signal from somewhere?

I think it works on sensing the pressure differential between the exhaust gasses before and then after the DPF. But in my simple head, with the DPF being empty, there shouldn’t be enough of a pressure difference for it to assume any blockage, which makes me wonder why it’s trying to regenerate itself so much 

This is all academic anyway as I’d have to fit a DPF anyway if I ever sold the car. Now the engine is in good order I might just do that anyway. It’s unlikely to clog now, and would prevent any issues at MOT time

You did delete the dpf from the car?

No, I physically removed it.

DPF “delete” refers to writing the DPF system out of the cars ECU software, so it thinks it hasn’t got one, and therefore doesn’t try to regen or use the DPF sensor info, etc

[STEMO]

Still a few niggles

Every now and again (each 50 miles or so) the engine ECU is initiating a passive DPF regeneration. This is where, for about ten minutes, it increases the fuelling, to “burn off” soot inside the DPF. This increases the heat in the exhaust and the engine and while as an occasional thing isn’t harmful, it wouldn’t do any good to let it keep happening. It also kills MPG.

In my simple mind, I don’t understand why it’s trying to do a passive regen. It can’t be sensing the DPF internals are getting full, when there’s none in there 

Mine  does one about every 300 miles, lasts about 10 mins, as you say. The idle speed creeps up from about 850 to 950, that's how I can tell and know not to switch off.
It's a pressure reading from the dpf that sets it off, so could the ecu be getting a signal from somewhere?

I think it works on sensing the pressure differential between the exhaust gasses before and then after the DPF. But in my simple head, with the DPF being empty, there shouldn’t be enough of a pressure difference for it to assume any blockage, which makes me wonder why it’s trying to regenerate itself so much 

This is all academic anyway as I’d have to fit a DPF anyway if I ever sold the car. Now the engine is in good order I might just do that anyway. It’s unlikely to clog now, and would prevent any issues at MOT time

You did delete the dpf from the car?

No, I physically removed it.

DPF “delete” refers to writing the DPF system out of the cars ECU software, so it thinks it hasn’t got one, and therefore doesn’t try to regen or use the DPF sensor info, etc

Well.....I know that, James
So...did you do it?

[STEMO]

So, if you take out the dpf and don't delete the software, it will still think there's one there...and do strange things....like a regen every farts end.

[STEMO]

https://www.vectra-c.com/forum/showthread.php?150367-DPF-remove-*without*-remap

[Raeturbo]

Yes because as far as the car knows it’s still on there until you tell the ecu.

[JamesV6CDX]

Ordered the new DPF - back exhaust tonight. Current one is rotten

[JamesV6CDX]

Every 40 miles or so, I get a fault code, DPF low effeciency.

Not sure that can be, given it's empty!!

When it does this, it over fuels, and stinks like a bad bbq

I fear I may just fit a pattern DPF 

[STEMO]

Every 40 miles or so, I get a fault code, DPF low effeciency.

Not sure that can be, given it's empty!!

When it does this, it over fuels, and stinks like a bad bbq

I fear I may just fit a pattern DPF 

Thought you'd ordered a new dpf?