I am trying to gear up for driving 100 miles round trip to the lake and back towing the skis this spring/summer. I have a 98 6cyl. around town right now we are getting 14-15 mpg. The 02 sensor went out shortly after We got the truck and I replaced it hoping to see a significant gas mileage improvement. So far I have not seen and improvement and it has been about 2 months. I disconnected the battery to reset the ecu after I replaced the sensor. I am planning on cleaning the MAF sensor with some electrical contact cleaner tonight. Is there anything else that could be causing such horrible gas mileage? The 4runner is getting worse MPG than the jeep...