Can a MAF problem....

[bull996]

...be intermittant on an Imprezza?

[ScoobieWRX]

Yep.....

Could potentially be a broken wire in the loom before the big connector that goes into the MAF sensor, maybe a loose wire not making contact in the connector itself, but it's very likely that your MAF sensor is dirty or has broken down.

Get some brake cleaner (evaporates very quickly like ether), soak a cotton bud with said brake cleaner and very gently wipe the small blob on the end of the sensor arm inside the MAF sensor itself (look through the tube that sticks out the bottom of the sensor and you'll see it. It's probably coated in crap which is why you're getting intermittent problems.

If that doesn't cure it then the MAF sensor is knackered and you will have to get a new one (not uncommon). I recommend contacting Grade-A Subaru for a second hand one for under £50 as a new one will cost you over £150 from a Subaru rip-off stealership. To remove the MAF sensor undo the 2 screws in the top of the sensor housing and bingo...job done!!

Hope this helps

[bull996]

Thanks-much appreciated.

[dnb]

Don't buy a 2nd hand MAF for a MY99/00 Scoob! It's false economy of the worst kind. They only cost £80 to £90 new if you know the right part to ask for...

The older MAFs are far more hardy and will stand quite a lot of use and abuse. Not had experience of the newer ones.