Just replaced O2 and no difference

[JonathanPrem]

Hi guys,

I just replaced my O2 senor and got it flashed but i still see no difference. I'm already on my second tank and its still giving crappy gas mileage. How long do i have to wait before it actually takes its toll or did i just dip out 260 for nothing.

[Qxxx4]

of my two years of ownership of my qx4 ive never gotten a check engine light....then last year for fun i hooked up a friends code reader and pulled 4 codes all o2 sensor related. I guess my check engine light is dead?

anyways, i still never changed the 02 sensors and am due for a plug change yet i still get good gas mileage....14L-17L/100km which is typical for the Q. Highway trips usually get me around 12L/100km.

If I pulled 4 codes and never replaced my sensors yet, Im pretty sure your gas problem could be something else, or maybe because you have the 3.5 its different.

Im sure youve checked out all the other stuff like fuel filter, plugs, air filter, those must be all in check right? i remember the qx4's got recalled for gas tank leaks, i think it was just 97-00 though. im yet to do mine I will eventually.

[JonathanPrem]

of my two years of ownership of my qx4 ive never gotten a check engine light....then last year for fun i hooked up a friends code reader and pulled 4 codes all o2 sensor related. I guess my check engine light is dead?

anyways, i still never changed the 02 sensors and am due for a plug change yet i still get good gas mileage....14L-17L/100km which is typical for the Q. Highway trips usually get me around 12L/100km.

If I pulled 4 codes and never replaced my sensors yet, Im pretty sure your gas problem could be something else, or maybe because you have the 3.5 its different.

Im sure youve checked out all the other stuff like fuel filter, plugs, air filter, those must be all in check right? i remember the qx4's got recalled for gas tank leaks, i think it was just 97-00 though. im yet to do mine I will eventually.

Only thing im due for is spark plugs. everything else is up to date expect the belts which i would do later in spring. If you can hear the fan does that mean you need to change the belts

[Buzzman]

Changing O2 sensors doesn't necessarily affect gas mileage.I had to replace mine a few years ago, and the mileage stayed the same.Actually the mileage was normal before I replaced them, and didn't really change after that.The good news is I've never had a check engine light again.What kind of mileage are you getting by the way?I just filled up this morning and calculated that my last tank gave me 15L/100Kms. About normal for the (mostly) city driving I do.

[Chuck Tribolet]

I guess my check engine light is dead?

On most cars, the check engine light should come on for a couple of secondsduring the lamp test when you first turn the ignition on. That will tell you if it'sburned out.

[JonathanPrem]

I use to get under 300 km on a tank. After changing fuel filter increase about 20kms. After changing my 02 its about 320-40 km/tank. plus im drinking mad slow to to save on gas cause im student a cant keep affording 55$ a week(actually only last me 5 days)