I was discussing my P0171 woes today and someone mentioned that after I replaced the O2 sensor ( and maybe some of the other stuff I replaced..) that I should clear the codes with a my scanner and/or unplug the battery to reset the computer. logic was that the truck has 'learned' to compensate for the problems and may still be adjusting fuel trim on the high side. I guess in other words...maybe the issues have been fixed but I'm still showing high trims, until a certain number of miles or drive cycles has happened and the computer re learns everything.
does that make sense?.....
does that make sense?.....