I got that code when I did my plenum swap, too. I used a digital voltmeter to check the voltage on the Throttle Positions Sensor - positive lead to the middle wire on the TPS, ground to a bolt/rivet on the strut tower. The voltage should be around .98-.99V when the throttle body is at rest.
Mine was around .80V when I got the code. Like was said above, try loosening the TPS screws and moving it a bit until you get the right reading then tighten it back up. I actually had to use a drill and enlarge the holes a bit to get it to read right. No problem since.
Jay