Your right there about the tail pipe test.
You might be on to something (giving it a good blow out). I don,t drive my truck to death but I don,t drive like grand ma either. There might be some trailer work to do in a few days and I will use it instead of the cummins.
Unfortunately there is no deserted road where I can mash it to the floor for a 1/4 mile. The roads here are anything but straight and the good roads have cameras on them. Having said that I,ill find somewhere and hope for the best.
Thanks, some very good points and cheaper and easier than a new cat!