Hey RB,, Long time since we have talked..Been trying to get some responce to a surgeing problem on a 2006 4x4 auto...set the cruse at 70. locks on ok... then rpm go down about 300, then up around 300 and you get this surge effect.. this is a standard truck with no toys,,, son tal's truck... he took it into the dealer they changed out the TSP, when he got it back the surging was still there.. went back to dealer, they said all dodge trucks had that trouble.. he called me about it.. i said i'd do the tdr, no help there yet, wrote a note to tdr but trouble wasnt addressed...you got any suggestions or a em add of someone that might tks Radar Doctor