47% increase in gas mileage!

[dibbons]

Just completed a 3,390 mile road trip in our 1996 Dodge Dakota 3.9L magnum with 3.55 sure grip, five-speed overdrive, and four wheel drive which now has 275,000 miles. It was purchases new by a family member (special order-fully loaded) from the Dodge Dealer in King City, CA twenty years ago. The first 1,000 leg was driven with the "check engine" light on and a trouble code P0132 (front O2 sensor fault). Gas mileage averaged 12.4 MPG. The second leg of the trip was driven after having replaced the O2 sensor on the road (dash light now off) and averaged 18.2 MPG. The original window sticker estimated the gas mileage as follows: 15 MPG city and 18 MPG highway. I was pleased to find replacing the sensor not only shut down the trouble light, but saved a lot of gas and money. Funny thing is, the vehicle seemed to me to run about the same both before and after replacing the sensor.

 

[dano]

Well that means before the sensor fix you were running rich. The down side to this is excessive fuel can damage a catalytic converter. They are sized to the engine and if more fuel than they are designed to operate in, they "run off" and melt the catalyst clogging the exhaust. Hopefully this wasn't the case so if you see degraded performance and sluggishness check the converters. was it the pre or post cat o2? Did you reset the ecu?

 

[toolmanmike]

I got 18.6 with my 96 Dakota 4 wheeler with a automatic on a 6 hour round trip. Not to bad. Those 3.9's are darned good. I have gotten 22+ with my 96 2 wheeler.

 

[chryslerfat]

After 200,000 I replace the O2 sensors on my cars because it is a heated sensor and may not read correct after that many miles.

 

[dibbons]

I reset the ECU and the O2 sensor I replaced was located before the cat-convertor.