I have a 2001 Galant,I recently had the 02 Sensor replaced and a tune-up still having same problem,it shudders between 45-50mph,only does it at certain times,I read a TSB and it said that this could happen with the A/T fluid breaks down causing a torque converter damper shudder,I contacted Express Oil Change and they said it was the torque converter,how can you tell which it is?

 

My car shudders around 70mph if I let go of the accelerator
the car wont shudder.. but even though when my car is parked
and neutral the engine vibrates and but if I shift into
reverse or Overdrive the car stops vibrating..
Idk what too do

 

Yea,my car does that too,it seems to do it worst when it's cold.When my car was idling my doors would shake and you could see the steering wheel shake.

 

My Steering shakes at idle too:/

 

Have your engine mounts checked,I had mine checked today all 3 are broke,plus I had a hole in my radiator hose.

 

I had replaced my motor mounts before except two..

Does your car still vibrate?

 

my galant shudders when idling too, more noticeably when in D or when the ac is on. When i flushed my A/T today I noticed it had an effect on the shudder. I can't say which way, but it was different.