Trani prob

Hi bob and ken I have a chevy 2500 with a 350 4L60E trani and it has 120000 on it. I reacently rebiult my trani and it is lazy. What I mean by that is in drive and reverse the engin revs more than the truck moves. I read in my maqnual that there is a Torque conveter problem. The truck is driveable and shifts with no unusial noises. There is a check engin light on and when I jump the diognostic port the light flashes twice than once two times. Than it flashes three times and than three times. Do you have any Idears for me? Thanks guys chris