pinnacle1 said:is all the black smoke normal? I know it sounds like a dumb question but I didnt expect it to be on even my economy tune. if I hit the gas pedal and load it up but let out before the truck takes off a crap load of black smoke comes out which Im sure is normal and explainable just wanted to confirm. and I went from 13 mpg stock to 9.9mpg on the looney tune.. is this normal too or do I need to have my sct checked out?