I have this code come up too on carsoft, 171 fuel supply system - along with 141 lamda regulation... I recently changed my MAF which brought back the power... 1 day after clearing all codes i still get the 141 error but that doesn't turn the light on by itself. Something else is going on that brought up the 171 code previously. Call me a pessimist but I'm expecting the mil to come back on within the week and the 171 code to return... reason being that I get problems with my idle... my next move was going to be the O2 sensors... I will post up if it comes back! If by any luck it stays off then in my case i was a faulty MAF contributing to the 171 code.