1999 outback cold engine stall - HELP

[CountryBoy]

I have had a problem for the past year or so...help! 1999 outback (Love it)!

Problem:
1) Cold morning, start the engine,,,I live where It is a long down hill (a few miles) to the bottom of the hill...
2) When I get to the bottom of the hill, I push the clutch in and the engine stalls.
3) Almost always the engine light comes on going down the hill
4) If I just turn the key to start the engine again, it will run really rough
5) If I cycle the key to the full off position and then restart it, it runs FINE.

The engine codes that are recorded (which I will post later) are indicating that the computer "got an input from something that is telling it to shut down a couple of injector" - the reason for running rough.

Both local mechanics AND the Subaru dealer claim the "idle valve body is bad" (I'll get the details also later) - but the local mechanic replaced this $400 part with NO difference...

Seems like the lean condition down hill combined with the cold condition is causing the problem - NO ONE HAS BEEN ABLE TO reproduce the problem on flat ground on in town! The codes are not pointing to a problem...the the resulting condition.

Any ideas?

Thanks

Mark

[nipper]

Tuneup would be nice as well as mileage.

We REALLY need the codes to help otherwise I cab just toss out some guesses.