Mad MAF readings on 2009 V70 2.4D
 

Hi all, my 2009 V70 2.4D is showing some odd readings from the MAF, way to high. I replaced it and the results are the same, I suspect a leak somewhere as swirl actuator is fine and attached ok.

I also noticed that if I activate the EGR in Vida, the MAF readings drop significantly:

With EGR running normally at < 10%:

V70 (0:cool:,2009,D5244T5,MMT6,YV1BW694191094274
Parameter Value
ECM-Air Flow Rate from Mass Air Flow Sensor 49,39 kg/h
ECM-Swirl actuator position 46,11 %
ECM-Air mass desired 237,7 mg/s
ECM-Air mass/stroke 480,3 mg/s
ECM-Intake air temperature (MAF) 81,86 °C
ECM-Intake air temperature (TMAP) 24 °C

With EGR activated to 100% in Vida:

V70 (0:cool:,2009,D5244T5,MMT6,YV1BW694191094274
Parameter Value
ECM-Air Flow Rate from Mass Air Flow Sensor 19,69 kg/h
ECM-Swirl actuator position 46,11 %
ECM-Air mass desired 237,8 mg/s
ECM-Air mass/stroke 188,4 mg/s
ECM-Intake air temperature (MAF) 81,86 °C
ECM-Intake air temperature (TMAP) 25 °C

As you can see the Air flow rate drops significantly.

This also seems related to the soot level in the DPF. The reason I say this is that after a regeneration, its ok until the soot gets to a couple of grams, then every time it boosts, the soot level rises massively but drops down again when it drops to idle.

If I thrash it and the soot level gets to over 25, it starts a regen even though I know there was barely any in it as it regenned only a few hours before.

Could a leak be the cause of all this? Or could it be a faulty EGR? I had the throttle body and EGR cleaned out a year ago so not thinking its that.

Also is that IAT MAF reading right? Seems way too high.

Any help or advice much appreciated.

The egr is not open in the first example.
And the air intake temp reading is faulty, which explain the slightly mismatch in the air mass reading in the second example , because air mass is corrected by temperature in calculation.

Maybe your engine is remapped with the egr programmed out, you can check that with a odb2 scan and a ecm checksum error.

Egr flow isnt regulated with only the egr valve its a combination with the egr and throttle valve which fine tunes it for engine load and regeneration.

Concerning the dpf behavior , it could be a broken or dpf pressure sensor.
But i suspect the ash (not soot) level is (too)high ( whats the mileage)?
Ash is permanent, can be removed manually but labor intensive , you can get cheaper refurbished dpf.s nowadays (dont forget to reset the ashcounter in vida)

Thanks, apologies for the delay replying. I cleaned an tightened up all the pipes i could find and that seems to have made a lot of difference, MAF readings are now what I would expect. The car is 175000 miles so I think you are right about the DPF, I got a new genuine Bosch sensor to replace the existing one, adapted it and the readings still fly up on acceleration when it gets a few grams of soot in there, so I think a DPF flush/Clean might be the next choice. Plenty of places saying they will do it for a couple of hundred quid so will try that next.

Only the opening up , baking and vacuum out ones...
Not the pour something in and let engine rune ones
Ash removal is very different vs sooth removal with burning point lowering

Read and understood. Ordered a BM Catalysts new DPF, for £257 including fitting kit instead, sounds like a good option for the price.

Indeed
Reset the ash counter in vida after installation