M50B25 NV Idle issue MAF or O2?

[Matich 6]

Last owner told me the MAF was toast however after doing some research, many have suggested it could be an O2 sensor failure where the DME (Bosch 402) has no lambda signal causing the car to not go into closed loop properly at idle. The car is running super rich and it can be smelt, I'm guessing that the idle calms down when MAF is unplugged because no reading from the O2 is required if no reading from the MAF is present, therefore running the engine off a set of predefined values. 

Hope it's as simple as an O2 sensor, a new one or a performance chip is fairly cheap and can disable the sensor. Hotwire maf's however are fairly rare and expensive. 

Trying to narrow down the answer as I don't want to spend money on a part that wasn't causing the issue, so far fluids, filters, spark plugs, thermostat, and ICV(cleaned) have all been serviced.

 

 

[zero 1162]

Have you checked for vacuum leaks? They are common on this motor

[Matich 6]

yup intake manifold was removed for proper inspection of hoses and to clean the ICV with carb cleaner, replaced the clamps on all hoses with new ones

[zero 1162]

Best to take it to a bmw specialist to get it scanned.

Otherwise you will just be throwing money at it.

Maybe some of the Wellington crew can recommend a workshop with good scanning equipment and knowledgeable operators.

 

This will save you alot of money in the long term.

[BM WORLD 1283]

these types of maf do fail

[*Glenn* 854]

Fuel pressure regulators can also bleed off pressurized fuel directly into the intake manifold when the diaphragm goes in them through the vacuum hose

[polley 916]

Pretty sure I've got a MAF around for one of these. Can have a looky if you want.

[Matich 6]

That would be really good if you could! Been trying to find one for awhile now