cel code PO450

[91CheapExp]

after the check engine light came on, I followed the advice on the forum and headed to the local Autozone store. In less than a minute the nice man said the code was PO450. On
http://www.troublecodes.net/Ford/96-01obd2mil.shtml
their listings says "EVAP system pressure sensor malfunction".
Any suggestions on what that means and what to check first? The cel hasn't reappeared yet.

Thanks!

 

[Opera House]

There is a three wire pressure sensor inside the tank that measures vapor pressure to verify the emissions system is working. BR/W should be 5V, GY/R is common, and R/PK is the signal. Could be just a bad connector, unplug and reconnect. The signal voltage should probably be somewhere in the middle, don't have exact details.