I have a Komatsu FG18SHTU-20 with a K21 engine, that when started cold, the idle will hunt for about a minute between 700-950 rpm before leveling out and running great. The O2 sensor has been changed(aftermarket),the MAF, regulator and throttle body have been cleaned, as well as the screen between the regulator and throttle body. I have a hand set and and have done relearn on all I can, with the exception of the idle air control. Whenever I try to relearn the idle air control, it just tells me to wait. Could the engine be doing a relearn on that in the time it is taking for the idle to stop hunting? Or could the hunting be caused by something else?