[igor@af]

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.