If a part is temporarily unavailable, you could substitute it with these parts:
Quality Throttle position sensor for Rover 800 2.0 16V Turbo 180 hp Petrol
Wide selection of new throttle position sensor for Rover 800 XS 820 16V Turbo (RS) Petrol 180 hp, priced from £34.48 to £151.24. Choose from 5 trusted manufacturers.
Throttle position sensor for ROVER 800 models
827 SI/Sterling Catalytic-Conv (XS) C 27 A1
827 24V (RS) C 27 A1
820 I/SI (RS) 20 T4H
827 Vitesse Catalytic-Conv (XS) C 27 A1
825 D/SD (XS) 425 SL1RR
825 D/SD (XS) 425 SL1RR
825 Si Lux (RS) 25 K4F
827 SI/Sterling (XS) C 27 A2
820 I/SI (XS) 20 T4H
825 SI/Sterling (XS) C 25 A2