My car has been running not 100% recently. Seems hesitant at 2.5K revs and is running lean as I seem to be getting 25mpg round town? Seems ok on boost.

It's been with my local Subaru dealer and they have checked the usual problems but now suspect the Map sensor.
What exactly does a map sensor do?

Thanks,

Graham H

 

reads the boost pressure in the manifold and converts it to a voltage so the ecu can see boost.

Simon

 

MPG seems fine for a turbo.

Any pics of a MAP sensor?

 

yes a picture and the position would be helpfull to me as well.
thanks

 

Could be reading low then as dependant on its output the ecu increases and decrease injector base pulse so if its output is lower than normal for a given boost you get less fuel.

bob

 

Bob, are you talking when in closed loop, or both open and closed?

 

I picked the car up last night and they have fitted a new map sensor and lamda sensor and it seems to be running much better now.
Especially noticable when cold and seems to pick up much more smoothly.

Just waiting for the warrenty people to confirm the work and parts are covered by my extended warranty.

Graham.