I have my 1992 Bird in for servicing a check engine light issue on the V6 engine. The mechanic says the returned code indicates the throttle position sensor. He says he replaced it twice and still gets the code. The reason (according to him) is that in idle there is supposed to be approximately .5 VDC on the sensor. He's reading => 5 VDC. He tells me there is no adjustment for this and he's continuing his investigation. Could he actually be getting defective sensors or is there an issue here that he doesn't understand? The car runs fine, i.e. no hesitation, rough idling, good acceleration, etc. but the Check Engine light comes on after about 2 and a half miles of driving.