I have recently bought a 96 Dakota 2WD extended cab. It is only getting 11.2MPG with 70%Hwy and 30%city driving. This is less than what I think it should be getting. It has new plugs, plug wires, new air cleaner, new exause from the CAT back. Does anyone have any ideas on how to improve the MPG? There is no MIL light on or anything but I wonder if replacing the O2 sensors would help, or would I see a MIL error if a O2 sensor was bad? The automatic transmission is just rebuilt and the OD is working fine. The rear gear is 3.55
Thanks for any ideas you can give me.

 

Yeah you should definitely be doing better than that for gas mileage, my '93 same as yours was getting 16 hwy 13 city with performance mods, try pulling the engine codes or have autostoned do it (not sure if the '96 have the turn key feature like earlier 1st gens, i was in one that did, but it was a rebuild so I dunno). A bad O2 sensor will only turn on the dumb dumb light in California models, but it will still be stored in the OBD, if you want try turning the key fore and aft w/o turning the engine and see if you get any codes thru the check engine light, like I said I don't know if the '96's will let you pull them

 

Yes, the 1996 Dakotas retain the "count the flash" error codes, but also have the OBDII connector so you can so to AutoStoned.
Just incase you don't know the specific procedure of how to get the flashes to start or what the codes mean, there is a link in the "FAQs" topic at the top of this section.

 

My 96 DOES have OBD I and OBD II... (I love it!)
But O2 Sensors can also go bad without setting a code. It is a gradual change when they decline, the code is usually only set when they are totally gone.
Also another thing that affects your mileage and often goes overlooked is your cooling system. If it isn't operating where it should, yhou won't get optimum performance.

 

idk what could be wrong, but with my 5.2 litre, im averaging 19 MPG..mostly highway and i dont do over 70 MPH.