Hi Darren;
Are some of the effects you expierenced engine stall, erratic running, preheating indicator light flashing, and high emission(odor)? If this is the case Pathfinder without the proper interface cable will not be of any value to you. Check the truck for line interrution or line to earth short circuit, OB2 defective, OB2 loose, metal chips at OB2, or the gap between speed sensor (OB2) and sensor wheel too great.