Anyone help forester cutting out

How is it going folks,

Just wondering can anyone help my brother in law has replaced the air flow meter on his forester turbo , and it is driving perfect now but the problem he is having now is that it keeps cutting out when coming to a stop and it cuts out when ticking over..

The battery was disconnected for about 30 mins but it's as if the ecu is still trying to reset itself . Just wondering can anybody shed some light on it

And is 30 mins enough time for the battery to be disconnected

Cheers john

Was it a new afm??

Silly question but did you plug back in the sensor connector??

It's a second hand one .

Yeah connector us in properly . It's a bit if a weird one

Old afm is showing up a fault but ticks over perfect only acts up when u plant the boot.

The second afm the car runs perfect but won't tick over keeps cutting out

Sounds like another fooked afm
I'd always try buy new afm's as you just don't know with used ones