shocking on fuel
 

hello everyone spidermonkey here from qld, i,m new to 4wding and to the world of jeeps. recently I came into ownership of a 2004 jeep cherokee limited 3.7 litre auto. never owned one before but so far has been a great vehicle except for the fuel usage. it,s shocking!! put $60 in ti on saturday and went to see a friend about 30kms away. fuel gauge showed just over half a tank. on the return fuel gauge showed just under quarter tank left after just over 60kms round trip. turns out am getting 18-20mpg on open road, shudder to think what town mpg would be. got it scanned for faults and showed up that drivers side pre o2 sensor was faulty, surprised to learn that these are fitted with 4 o2 senors. would this sensor be the cause of my excessive fuel consumption?? has bee running rich on start up. else it,s been good and quite happy with it so far fuel problem getting fixed.

It certainly would be a likely culprit. I don't know what the 3.7L engine should deliver but that is terrible and for comparison my daughters 2003 grand cherokee which is heavier and with a 4.0L engine averages in general driving and commuting (more highway driving than stop start) around 11.6L/100kms and this climbs to around 14.2L/100 when towing a 2T horse float.