I want to thank Racer guy for the help on is this code on how to fix this problem he was right on the money with what to do. Okay how long will it take to for truck to clear up? Still runs rough some times and sometimes while driving truck wants (stall, lacks power and runs just ruff ) Could the spark mods be bad? or does anyone have a idea on what magic wand to use? Any help or ideas would be of great help...

Oh will check here first before i spend any money on parts. Lots of money on parts trying to get that P0401 code to go away. Did have the code for a while hope i did not screw the truck up. BUT THE CODE IS GONE... SO FAR

1999 f-150 4.6 139,000 miles
Parts changed
SPARK PLUGS, FUEL FILTER, 4 02 SENSORS PRETTY MUCH ANYTHING TO DO WITH THE EGR SYSTEM AND A GOOD KICK TO THE TIRES MORE THAN ONCE AND NUMBERS OF SMALL THINGS IN ALL ABOUT $300.00 PLUS OR MINUS