TPS=Throttle Position Sensor. It's located on the throttle body and indicates how far the throttle is open. You may want to unplug-replug the connector to it to make sure you have a good connection. You have to remove the entire upper intake manifold to get to the gaskets underneath. Lot's of stuff to disconnect & take apart. (Recommend getting a manual if you haven't done this before...)
BTW: Look up CEL codes
here 
