Throttle Angle Sensor

I have a 1988 Acura Legend and the ECU code says its the throttle angle sensor. Where is the throttle sensor located? And what does it look like? I am using Haynes and the description is "not visible" . It shows it in the vicinity of the throttle body. Is it located in the throttle body assembly? Or near it? Is it replaceable or do I have to replace the entire throttle assembly? Thanks if anyone could answer with a picture or a good description.
Is it expensive or is that a dumb question (of course, its an Acura). Shuld I buy new or from a yard or does anyone recommend a place.

The TPS (Throttle Position Sensor) is located on the throttle body and has a plug running to it actually should be 2 electric componants on the throttle body one the TPS the other the IAC
(Idle air control ) TPS should be black in color http://images.search.yahoo.com/search/images?p=Throttle+Position+Sensor&sm=Yahoo%21+Search&fr=FP-tab-img-t&toggle=1&cop=&ei=UTF-8 this link will show you lots of pics so you know what you are looking for
hope this helps