2000 Lexus ES300 - low idle when I shift to drive - is it the torque converter? how to clean torque converter?

Hey there - when I shift to drive the engine drops to a very low idle and the RPM is around 1500 which is too high.
If I drive it won't let me drive past 40mph.
Engine shakes.
Transmission drops to lower gears after each time I try to accelerate.
Also, Transmission kicks from time to time.
Also, the ATF (transmission fluid) is very dark brown color and dirty.

Do you think I should change my transmission fluid?

Do you think the issue could also be the Torque Converter?

How do I clean out my Torque Converter?

Please let me know. Thank you

Based on your description, it's possible that the low idle and other issues you are experiencing with your 2000 Lexus ES300 could be caused by a faulty torque converter. However, there could be other factors at play as well, such as a clogged fuel filter or a vacuum leak.

Before attempting to clean the torque converter, it's important to determine whether or not that is indeed the problem. One way to diagnose a faulty torque converter is to have the transmission fluid checked for metal shavings or other debris, which could indicate a problem with the converter.

Regarding changing the transmission fluid, it's generally recommended to do so every 30,000 to 60,000 miles, depending on driving conditions. Given the dark color and dirty appearance of your ATF, it's possible that it's overdue for a change. Doing so may help address some of the transmission-related issues you're experiencing.

As for cleaning the torque converter, this is not typically something that can be done by an individual without specialized equipment and training. It's best to take your vehicle to a professional transmission shop or mechanic who can properly diagnose and repair any issues with the converter or transmission.