Certainly sounds like a sensor, do you have a multimeter of some sort? start testing the readings from each sensor... you can download the Honda service manual for your lude from here(just sign up and go to "Manuals" link on main page) http://www.hondahookup.com/manuals/

List as "Honda Prelude (93) Service Manual(38Mb PDF)"

Also, you throwing any codes?? make sure you drive it around a bit, I think it takes a couple drive cycles to pick up intermitten sensor failures...