My mechanic has diagnosed a failing throttle position sensor on my 1992 Subaru Loyale 4WD (non-turbo). (First, he replaced the plugs and wires.)  Neither he nor I can find a replacement for less than $250.  That seems excessive—does anyone know if there’s a non-OEM version that’s cheaper, or whether one from another model would work?  Is there an intemediate repair between wires/plugs and the TPS that I should try first?
 Thanks for any advice…