Reader Question: I have a 1994 Lexus GS300. I have regular maintenance. The “Check Engine” light keeps appearing, will stay off for a couple of days, and then comes back on. The repair place says it might be the computer.
Do you have any suggestions?
I think I would find another repair place. Any place that just assumes the computer is bad is usually NOT qualified to diagnose the job in the first place. Seldom do car computers fail, and the problem is usually one of the many sensors on the engine.
The check engine light should come on and off as the computer senses the problem and tries to reset itself and clear whatever the problem could be.
The next time you start the engine the computer will run through its checklist and make sure things are working like they should. When it sees the problem, it turns on the check engine light.
Did you read my article about check engine lights? It might help you understand how the system works and what causes and does not cause the check engine light to come on.
I would recommend either you get a diagnosis of the problem from the dealership or from another shop with more experience with Toyota and Lexus. Lexus is made by Toyota.
Paying the fee for a proper diagnosis will save you time, money, and frustration than paying someone to guess at what the problem is.