I UNPLUGED MAS I saw the thread about doing that so I did it's been off for 2 wks it never ran so good of course ck eng Lt and code I do have a bad rear O2 sensor just to hot in Texas at the moment to change it. Just filled up looks like mpg didnt change much 18- but I don't DLISI LOL!!

 

18-20mpg sounds about right. I have a 93 and average that in the city. When I get on the highway it will jump to about 20-22mpg.
where are you fueling?
Check your plugs and make sure you're not running rich, if you're check your gaps and your pre-cat oxygen sensors since their main job is to ensure you're not running rich.
rear oxygen sensors are to verify everything is being burned efficiently.