First of all, thanks SO much for all the thoughtful ideas and suggestions on my original posted issue. I am game to try any mechanical work myself (grew up helping dad hook mufflers up with coat hangers, etc.). The hubby found an MAF on eBay for $25. But before we even came up with a real plan, a new and rather dramatic turn of events....
Original sob story from Nov. 6th: [1998 Subaru Outback stalls at traffic lights after driving 30 miles] This just started a couple of weeks ago. The car seems fine when driving locally, but when my husband drives it to work, or home again, it starts acting up. He drives about 30 miles on the highway. At either end, he has a fair amount of stop and go traffic. Most days now, the car will stall out while he's stopped at a light.
Fortunately, it starts right up again.
We've taken it to 2 different mechanics who cannot find anything wrong with it. Our own trusted mechanic ran all the computer diagnostics and said the code came up suggesting replacement of the Mass Airflow Sensor, but he didn't feel at all confident that would solve the problem. And it would cost $500.
The Outback has about 150k miles on it. Oh, this is my husband's description of the stalling process:
"Usually when it stalls ALL the lights come on. But sometimes just the yellow "AT Oil Temp" light flashes for a bit. What I've also noticed is a sound coming from the front, passenger side as the car's slowing down, kind of like the noise a flat tire would make, or if there was something caught in the wheel."
[Bizarre update 11/10] Yesterday, my husband was driving home from work and the noise he'd heard before (as car was about to stall) got worse and worse. He said it sounded like the engine was about to fall out! He put the flashers on and drove very slowly home to our mechanic. The mechanic said that five wheel studs were broken off and it was a miracle the tire didn't fall off while he was driving.Mechanic is currently fixing the tire while the whole family carpools grumpily in the mini van.
But how can this be a coincidence?!? Obviously the intake system didn't cause the tire to fall off... the loosening tire couldn't cause the car to stall, surely?!? But the noise of the tire is what my husband was hearing each time the car was about to stall!
(Steve, I don't know for sure which engine it has, but I've been very disappointed in its fuel consumption. It often gets less than 20mpg driving around town.)
Thanks in advance for brilliant explanations.
--Emily