Just this evening I took dash apart and removed the control box. It's got a date code of 2001 and a "www" address, so it's obviously been replaced. Thats not to say it could still have a problem, but I kind of doubt it. Since I can see behind dash now, I'll investigate some of the vacuum valves to see if they are working correctly. Maybe broken diaphrams in there.

I'll locate the evap sensor and test. I think the cabin sensor is in the roof panel by the dome light. There's a hole there I can stick the tip of my finger in, looks like a cover or something is missing. What would it look like, this sensor?