ok guys this really sucks......i seem to have the same problem as alot of these other people on this site, my main concern is that im running test pipes....no cats. this is causing my SES light to be on constantly, not a big concern for me but could this be causing my engine to run ****ty? i have it down at the shop right now and ill be checking wires, plugs, fuel filter tomorrow but could it be an o2 flaw? it seems to do this only at half throttle. when trying to accelerate without down shifting but not quite at the point of lugging the engine. and example is being in 6th going 55mph and trying to gas it w/o down shifing. i get a bad vibration i can especially feel it in the stick. any ideas guys?