I had purchased my 03 GS300 about 8 months ago and Im happy overall with the vehicle but as of late I been feeling that the transmission getting tired. It doesn't slip nor does it have any erratic problems but my only complaint is that the car feels really heavy and sluggish now no matter how hard I accelerate.

I was doing some research and heard that these transmission are known to have bad shift solenoids. My engine light is NOT ON, I have no DTCs and the trans fluid is nice clean and red(I am not sure when the trans had been flushed and trans filter cleaned). How can I tell if my shift solenoids are going bad? I was looking around for a used A650E, its going to be a cheaper route swapping transmissions than replacing the expensive shift solenoids.

Are there any other issues with these trans or torque converter? What can I do to get a little more torque without breaking my bank?