Hey guys, The problem seems to have just started recently. The best way i can explain it is a shudder kinda. Its like driving a five speed and say you start slowing in a high gear.....you get that slight bucking, but in my car its not quiet that violent. It seems to do the same thing right after the convertor locks up and while at low speed you barely giving throttle i can feel the car slightly bucking. it maybe engine related, but i figure i would look at lockup issues first. Ps. also the car has unlocked at about 75 on highway a few times. You just cruising and it unlocks and after a mile or so locks back up thanks guys

 

This is almost certainly engine misfires causing the PCM
to unlock the converter. Have to hook up some logger
and see whether it's one cylinder (mechanical something
to fix) or all of them at random. Though I had this problem
following converter+headers install and I couldn't see bad
misfires attending the unlock, killing the tables for sure
did make it go away.