please help me. since i bought a 98 sport for my wife the tick over has been playing up,some days it ticks over as it should but other days it won`t tickover below 1500rpm ,i`ve had it in a subaru dealer but he was left scratching his head also , any body else had these problems ,please help

 

Have you had the idle control valve cleaned? and the lamda sensor checked? i dont know if the sport has a MAF sensor?