MAF Range Discrepancy

[Tikka7mm08]

My wife's D4 has gone into restricted performance mode a couple of times. Including after cleaning both MAFs.

I looked at the MAP sensor today (photo) and it was filthy so cleaned that and no faults showing.

On live data I noted one MAF bank was at 18 and the other at 1. It wasn't until very high revs they started matching each other and when returning to idle the '18' bank would follow the other one down to a single digit value and then move back to 18.

What is the normal MAF range and is the 18 bank at fault or the bank sitting at 1...or neither?!

[Tikka7mm08]

I also swapped the cables over between the two MAFs and the low reading transferred to the other bank.

[DiscoJeffster]

It’s a sequential turbo setup so bank 1 isn’t engaged until after 2500rpm when the second turbo is engaged and the second maf starts to work.

It’s normal for only one to be active at idle

[Aussie Jeepster]

As a newbie to the 3.0 Diesel, are these things simple to clean?
As in, unscrew the retaining screw and clean them with ??????
And are there MAFs and MAPs - are they all as easy to get to and clean??
There are some jobs I don't mind doing - I just like to know how!
Alan

[Tikka7mm08]

Very easy to clean with electrical contact cleaner or CRC MAF cleaner...don't use other cleaner (brake cleaner) as they can leave a residue behind. The MAFs are right by the air filter and can be undone with 8mm nuts. The MAP is under the engine plastic top cover that pops off. Just a T20 or 25 to remove the nut and it pulls out. Clean with MAF cleaner and don't poke anything inside it to clean as you may damage the sensor.

[Aussie Jeepster]

Very easy to clean with electrical contact cleaner or CRC MAF cleaner...don't use other cleaner (brake cleaner) as they can leave a residue behind. The MAFs are right by the air filter and can be undone with 8mm nuts. The MAP is under the engine plastic top cover that pops off. Just a T20 or 25 to remove the nut and it pulls out. Clean with MAF cleaner and don't poke anything inside it to clean as you may damage the sensor.

Thanks heaps.

[Eric SDV6SE]

And don't use compressed air either on the MAP, even though its tempting. You WILL damage the sensor.