1998 Lexus GS 400 Catalytic Converters

Hi RBaldree -

Did you ever find out what was causing your check engine light to go on? I also have a 98 Lexus GS400.

It does sound strange for the cats to go out after 60,000 miles especially if they are the Lexus cats. There are other things which can make it appear the cats are failing. The most important thing to do is to find someone who has an OBD2 scanner and plug it in under the dash below the steering wheel. You want to be able to access the freeze frame data. That is the data which was captured at the time the light went on and the code was set. By the way, what was the code? Did the light flash or just remain on? You may only have 1 side causing the error. The data and code will remain as long as the light is on. Once you have the data, post it and some one might be able to steer you in the right direction.

One note - have the spark plugs been changed? If not, on the scanner, look for misfire data. It could indicate a marginally running cylinder.

Hope this helps.

- Kevin