Post Install O2 Sensors '93 Ls 400

[toothguy57]

I'm back. I replaced all 4 sensors and disconnected the battery for several hours before starting the engine. The " check engine light " did Not come on. I drove the car approximately 150 miles and then the check engine light came on again. I took it to a lexus dealer and they ran the on board diagnostic and came up with the O2 sensors . I " confessed" that I had replaced the sensors and asked them to reset the error codes which they said that they would do. However, the "check engine light" was on as I left the dealer and it is still on although it is sometimes dim and other times it is quite bright. However , it does not flicker . Again, I would appreciate any feed back regarding :

1. Am I, as an amateur, able to reset/cancel the error codes ?

2. If so, how do I do it?

3. Are there any other troubleshooting procedures that I could employ ?

[landar]

Charles, you can check codes and clear them yourself without any special tools. Read this tutorial carefully and it will tell you how to do it.

http://www.lexls.com/tutorials/intro/codereading.html

Are you sure that a connector on one of the sensors you replaced did not wiggle loose?

[Yamae]

>3. Are there any other troubleshooting procedures that I could employ ?

It seems to me that your symptom "150 miles run and then the check engine light comes on" is caused by the abnormalityof the emission system of your car. You'd better to check the efficiency of the CAT, vacuum leaks and others. In my experience, most of those were caused by the air leakage at the exhaust line. Some old cars had failed CATs.