I'll check the gas cap. And see my Autozone store. I did search for OBDII eariler and found some interesting scanners that use your PALM. http://www.auterraweb.com/
$219. I haven't found one for $150.
o2 sensors- I'm assuming the scanner will tell me which of the 4 o2 sensors are bad. The front 2 are $140 each. I've put o2s in my other cars and if your willing to splice them in, the Generic Bosch 4 wire, is less than 1/2 that price.
Thanks for the suggestions!
I'm planning to keep this car for 300k, so a OBDII scanner might be a good addition to my tool collection.