How do I locate the low pressure port .
air conditioning charge on 2004 Lexus LS430
The Low pressure line will have a plastic cap with the letter L on the cap which you will unscrew. probably back toward the left rear next to firewall.
Follow the fattest line from the AC compressor. Start at the rear of the AC compressor and follow the wide line (low pressure side) it might be right off of the AC compressor manifold. I know that on other Lexus models the low side port is part of the hose manifold at the compressor. They also had a light blue cap with and "L" on it. Good luck.