[1998 Forester fuel economy]

***Update***

Well, no improvements on fuel economy so far. Over the last two days however the car started to stutter and almost stall while idling in gear. Especially for a brief period after starting to accellerate from stop.  Put the car in park and did a very light engine rev, it's having the same problem, at about 1200rpms it gets very rough. After that it smooths out again.  I'm starting to wonder if my coil pack is bad.

 

No engine codes yet despite that bad running.  I bought a live scanner tool, It calculated mpg based on MAF and vehicle speed. Around town driving it calculates about 22-24mpg, freeway it calculates about 27-30mpg. Averages around 23mpg with stopping, accellerating and what not. So something is still causing it to dump to much fuel in as far as I can tell.

 

Anyway, whatever is wrong with it, was also a problem on my 2001 Outback, it too had issues with idle when light throttle was applied with a load. Maybe not the same root cause, but it's almost identical in symptoms now.

. Mr.carb have you solved the issue yet? I have all of your symptoms in my ej25d legacy..I average 16mpg . It has rough idle and I out it in neutral to smooth it out at stop lights. I started to change everything