As a new owner what is this maf that comes up regularly & what does it do please?

 

The Maf basically monitors the air entering the air intake, and sends a signal to the ecu which adds fuel to be burnt with the air. If the maf is faulty it can cause the ecu to make the engine run lean or rich with bad consequences.

 

Maf = Mass Air Flow

 

http://www.autoshop101.com/forms/h34.pdf

In a Subaru it is a hot wire sensor.

 

thanks for your replies lads. How do you know if it is knackered as someone mentions rich fuel can cause problems.I have only had my car 2 weeks driving it sensibly it has only done 120 miles on £35 fuel.Also when it is fully warm it is running at 1400rpm (far too high) could this be the maf & how much do they cost &are they easy to install. thanks

 

From reading previous posts on SN (ie. no actual experience of these problems myself), a failed/failing MAF will manifest the following problems:

• "Hunting" at idle - engine doesn't hold a constant rpm at idle
• Engine threatens to stall when pulling up at junctions
• Engine stalls when pulling up at junctions
• Poor fuel economy (difficult one to quantify as scoob mpg's are rarely good, excl. pslewis )
• Check Engine Light (CEL) flashes for ~30 seconds under heavy acceleration

Hopefully they'll be some more detailed symptoms posted soon......