wildtypitch

Lol just the sensor! DPF good as new and 1 yr warranty

Just an update on proceedings. Went to a DPF specialist who removed the dpf, stuck it in his machine and flush cleaned it. Result - limp mode now deactivated and car running normally. No warning lights. Exhaust gas temperature is still putting out a 999 value. It's not causing an error now but he said it might when it tries to regen and suggests replacing it. So I'll buy a new one and fit it myself. DPF clean done in 3hrs at a cost of £320 Inc VAT.

Sensor under £50. I'm also inclined to think that the ECU is reporting that 999 as a false number to shut down the DPF. Too convenient a number... Tried getting an ohm read on the sensor late last night but fiddly. Think I got a 1k reading but will need to do again properly. Could raise the temp and see if there's a difference while throttling. Think it's best I just take it to the DPF shop and let them figure it out.

Or a nice graph. Things to note: Differential Pressure is being recorded and in line with engine load. Assumption: DPF Sensor working Input gas Temp reading well but DPF Output gas temp Is stuck at 999. Seems like a sensor malfunction. Assumption: If it can't read the output temp is can't engage the regen or control the temp. High pressure EGR closing. Not sure what to make of this, it's constant 100%. Does that mean it's completely open or recirculating at max? So based on this I'm considering replacing the sensor myself as it's very accessible. Or might I be reading the data wrong? I've disconnected the exhaust temp sensor and checked the obd and I indeed get P246F (Exhaust Gas temp Sensor circuit range/performance) error. Plug it back in and no P246F error jus the existing P2463 (Particulate Filter B1). Perhaps when it goes and reports 999 temp it's still considered within range?

So got my little obd Plug and pulled some data below while revving the engine stationary. Oil Ash residue seems implausibly low. Any clues in that?

It was replaced before I bought it over 4 years at least. I've been unaware that the noise was irregular so can't really say when it started or if it's gotten worse.

I've found these forums really helpful so thought I'd ask here about an issue that hasn't turned into a problem yet but I'd like to hear your thoughts. A couple of mechanics have mentioned the strange noise the engine makes when revved. You can notice it more the higher the revs. Had to explain but I did a video which around half way through I revved up and it becomes apparent. Just concerned it might be causing damage somewhere. It's not something new though. YouTube clip

Can't wait to see failure in actual numbers!

Interesting, before I pull the trigger on the clean I'll use the VAG DPF app with the otgb II dongle arriving tomorrow to monitor levels. If it displays such detail.

The sensor is really accessible so I took a multimeter to it and read a 1k ohm signal to ground which should be about right. If it was damaged it expect either a short, no circuit or a very high reading. It's no guarantee but makes me think it's less likely an electrical fault with the sensor.

Tricky, sensor £25, mechanic 1hr £80, VCDS adapted £60. Considering there's no warning lights for the sensor... Maybe I'll suggest they try changing the sensor before the flush but don't really want to start telling them how to do their job.

Yes seems logical should have triggered regen at around ~25g soot measured. That fact that from dpf warning light to Glow light and limited performance was a few miles doesn't seems highly unlikely the cause is ~50g of soot being created. Just got off the phone from a DPF cleaning service which will remove the DPF and flush it in one of those specialist machine who seem confident that the pressure difference will be because of the ash oil and flushing it will bring it back to like new. £325 with 1 year guarantee. Given the mile sunder the belt I think this'll be the most sensible option.

What exactly are those figures? Is one ash and the other soot? Confused by the definitions calculated and measured.

The feedback I got didn't stipulate soot or ash oil. I'm aware of the dpf warning light and it happened once before and quick run on the motorway cleared it. It happened this time but a few miles later I got the limited performance and more warnings.

Thanks I'll look into it. Any North London recommendations?