I have a 2001 Sport Trac. 82,000 miles and it has a 4.0L V6. It started missing. I changed plugs and wires. Didn't help. When I pulled the plugs they were red indicating it was running too lean. My mechanic pulled the codes. Misfire on cylinder 6, random misfire. He speculated the baro sensor was not right. I had the Ford dealer flash my PCM. It ran great for about 3 days afterward but it is doing the same thing again. I also changed the fuel filter with no change. I am thinking it may be a fuel problem but it could be a firing problem. Any help would be greatly appreciated.