I bought the truck with 6K on the motor and most things redone. I've put 55K on it since with regular maintenance and tune ups, but I'm having some power issues now. The engine has always had a slight down and up power surge that I could barely notice when cruising at steady highway speeds. Now the idle has become rougher than normal and when I give the throttle more than a little, there is a bogging, hesitating power loss. If I floor it, it goes like a champ! This problem isn't to bad on the initial drive, but if I stop somewhere for a few and get back in to go, it's bad for a few miles before it works itself back to semi-normal again. I do have a small leak in the muffler that I am about to replace. Before the recent tune up I got a code 43 in the starter signal, but after the tune up (plugs, cap, rotor, air filter, pcv valve) and resetting the EFI fuse the code was gone. Any ideas on the possible causes of this? Thanks for the help.