85 Westie started out getting 19+ on the road, 18 or so around town.  Slowly has decreased to 15+ on the road, 17 around town.  

The decrease I can understand, may need a tune-up.  But why the bigger decrease in road mileage?

  Data:  trip #1 with o2 sensor connected: 140 miles /9.683 gal= 14.46 mpg
  trip #2 with o2 sensor dc'd: 140 miles/ 10.316 gal=13.57 mpg
   
  difference, I think the fuel economy is actually better with the sensor dc'd, but I can test that later. 
  I was truly hoping the fuel economy would improve by dc ing the o2 sensor.  I'd like to know what is "average" for a 84 westy.  Average-as in across the board if you toss out the 10 % that are excessively high and the 10% that are excessively low.   
  End result in mpg testing is that when my family goes to Florida next week, we have to take the 97 Suburban now because the mpg is better...(wife giving her victory snicker in background).
   
  Question: If the o2 sensor gives the ecu feedback and (yadda yadda) gives you the best mpg, AND I am comfortable with the very minimal mpg loss with it dc'd, can I run without it forever without hurting anything since it drastically improves the driveability as above???
   
  I can't wait to hear the thoughts of the list.
  Jay in Seymour Indiana

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