2003 Disco II, 108K miles, Three Amigos illuminated (Part due tomorrow). I had the codes checked and besides the P1590 fault code, the vehicle also registered P1663 and P1664 fault codes. Could this be the throttle position sensor gone bad, or could it be related to the Three Amigos? I can easily pick up a new TPS, but just wondering if this is necessary? Most research indicates HDC, but my local Rover shop says unrelated??? Most recently the water pump failed and seized snapping the Serpentine belt. While I had it apart, I replaced the pump, power steering pump, and Radiator as well as transmission cooler lines. Any input would be appreciated, thank you.