# Change sensors to improve fuel economy?



## hublocker (Jan 6, 2005)

I'm getting terrible mileage with my 1995 Nissan V6 .

Someone suggested changing the O2 and coolant sensors.

Is that a good idea?


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## RobXEV6 (Nov 3, 2009)

How bad is 'terrible gas mileage'?


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## hublocker (Jan 6, 2005)

5.6 km per litre or

13 mpg


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## smj999smj (Jan 1, 2006)

Depending on your driving environment, I wouldn't say that's "terrible." WD21 Pathfinders were never known for good gas mileage and the US EPA rating for a 95 Path V6 4x4 is 14mpg city and 17mpg highway. If you are using a gas with ethanol blended in, that could drop that rating slightly. Also, keep in mind that rating is for a "new" Pathy in 1995 and doesn't take into account 17 years of wear and tear! That said, if the oxygen sensor is original, it certainly wouldn't hurt to replace it as they do lose some efficiency over the years. If you have an ohmmeter, you could test the ECT to see if it is within range of the service manual specs. Making sure the engine is properly tuned up (stick with genuine Nissan or NGK parts for best results) and keeping tires properly inflated help, as well. Perhaps the most influential thing when it comes to gas mileage in any Pathy is the driver's right foot!


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## ajriding (May 10, 2010)

On my 91 v-6 engine in a pickup 4x4 I get about 17 city, 21 hwy. many many miles on it. I use an EFIE to trick the computer into thinking its getting less air. this leans out the fuel mix and actually gives it more power. You can also trick the O2 sensor and have the same effect - it all just wires into the electrical wire going into the computer. Very simple to do. The only danger is leaning it out too much and burning out your valves and plugs, or worse... I don't go crazy with it and it works well with no issues for the years I have done this. I just set it to the maximum power setting and leave it alone (the dial on about 7, with 10 being factory setting).
If your truck has a lot of miles then your compression has dropped and you will not get as much power/ good mpg, so mileage will drop over time.
And everything he said above about keeping engine tuned up.


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