How do you read engine codes 94 Lexus ES 300?

According to OBD-II website, the ES from 1994 had OBD-II installed on the car. You can get an OBD-II reader at any auto parts store or they can even read it for you at Autozone or a store like that. The plug for the tool should be near the steering wheel, probably below and to the left, as it is on my LS. If you get a tool, it will tell you what the codes mean. Good Luck, HTH.

The '94 Lexus ES300 is indeed OBD-II. The diagnostic port is located in the fuse panel that is just left and below the steering wheel.

Connect a jumper wire between TE1 and E1, switch on the key but don't start, count the engine light flashes. codes are in two numbers for example if your codes shows 23 number, engine light will flash two times first and after 2.5 seconds the it will flash continuously 3 times then the next code will start to flash after 4.5 seconds. count the codes and find the solutions.