1998 Jaguar XJ8 TPS sensor

I recently purchased a new-used engine for my jag, when I got the car back the check engine light was on and it was in limp mode. I asked the shop and they said that my throttle body was out and I needed to replace. First is that a piece that should have come with the engine, and when I hooked my car computer up the code said tps sensor, so I contacted jag to buy a new sensor and they siad I have to buy the entire throttle body and the sensor can not e reprogramed. The cost of the throttle body from jag is 3000 and no one sells the sensor, although I have seen them for sale refurbished. Is it possible to refurbish this one on my own or due to the tps sensor am I just out of luck?