MAF Sensor

[Hightower]

I have been getting progressively more concerned at the lack of mpg I'm getting from the car recently.
After some browsing through the web I've found that the culprit may be the MAF sensor.  If it's faulty it can lead to incorrect readings being fed to the ECU which in turn overfuels the engine.  End result, poor mpg.  It may also account for the rising levels of black smoke coming out of the rear end on acceleration.
I did have a look at it, and it does seem very grubby.  Now, can I clean this sensor and if so, how?  Not sure if there is any way of actually testing the sensor to see if it's working correctly before I decide whether to replace it or not.
Any views would be most appreciated.

[muddyweb]

You really need to get it on Testbook to find out.

My Td5 had a faulty manifold pressure sensor, so the ECU was getting confused as to how much air there was.

It might be that the a reset of the fault registers will cure it.

[Hightower]

My man in Rushden had to send his Testbook back for fixing today but is expecting it back on Wednesday.  I'm gonna pop back over there then to get it checked out.

He didn't seem surprised that it could've failed either.

Oh well, another thing to fix  :(

[td5disco]

I'd go with the Air pressure sensor on the inlet manifold

[Hightower]

Thanks guys.

You don't happen o know the part number of the air pressure sensor do you?
Rather ask than go thru the pain of H@rtwells parts dept YTS staff!!

[td5disco]

mhk100640

[Hightower]

On testbook today, lots of error codes:
- Low inlet pressure
- Over boost
- Overheat
- etc

Too many to make any sense of.  So cleared them all and took the car for a 10 min drive.  In true LR fashion got back, plugged in testbook again, and NO codes!!!  Aaaaaaaaaaagh!!!

It's going back next week for a service, so hopefully something will have errored by then  [-o<

[Hightower]

After neary a month, got an error code logged when we checked today.

EGR Valve Modulator is faulty.

Off to H@rtwells tomorrow and we'll see if we can get back up to 28mpg.  Fingers crossed.

[Range Rover Blues]

I wouldn't expect EGR to afversly effect either the MPG or cause the black smoke you describe but I do remember reading an interesting article in one of the comics this month about a staff car that had the same problem (freelender I think) and you initial diagnosis was correct in his case.

[Hightower]

Well, I changed the EGR valve modulator, and it doesn't seem to have made much difference at all over the past couple of weeks.

Having read a few bits 'n pieces on the web, the symptoms I am getting could be caused by one of the injector sealing washers beginning to fail.

How likely do you think this is?  There's still nothing on testbook of any note.  Do you think that it is worth looking into?