The hose - this hose will make a serious vacuum leak, and will absolutely make the car run rough and/or stall. There is a specific part for it, a molded hose with two 45 degree bends in it. I have found that fuel line hose works fine in that spot.

Do check the OVP relay, it will cause stalls, inability to idle, and the ABS light to come on, among other things. Kind of a notorious part really.

Check for dubious repair attempts. Often when there is something like a bad vacuum leak, instead of fixing the problem, people tend to do something else to compensate. If you've fixed a problem and now the car runs worse, do look for hack repair attempts.

Thanks to everyone who suggested changing the OVP!

This cured the non-starting problem, and a lot of the rough idle.
The related tranny shifting problem has gone away, maybe.
Haven't given it a real test run - probably still going to have to replace or clean the O2 sensor.

update: the old OVP caused the tranmission shifting issue, and that has gone away.
Still need to replace or clean the O2 sensor, but no real urgent need to do that right away.

Changed the O2 sensor yesterday, and noticed the check engine light was off as I started to drive.

Darn, if the light didn't turn on again, after about 15 miles.

Checked the code when I got home, and there was 17 again, as if I didn't change anything.

:confused::confused::confused: