New guy looking for some explorer answers

[Nicks91]

I'm looking for anybody that knows why a lean mixture code would be in continuous memory on my '91 explorer, but when I go through the KOER test everything tests normal. Basically I'm not quite sure why the check engine light is coming on in no particular pattern and the oxygen sensor has been recently replaced. If anybody has any ideas I would greatly appreciate them.

 

[JDraper]

Welcome to the site!

Have you tried to re-set the computer to see if the code goes away? This can be accomplished by un-hooking the battery for 5 minutes. Sometimes a code gets put into memory and won't go away until the memory is re-set, even if the problem is rectified.

Now, if the code returns, it's time to go looking. The MAF could be dirty/damaged giving erroneous readings, there could be a vacuum leak...etc.

Do you have any other symptoms?