Ive been listening to you all talk about this 02 sensor or sumthin...and getting better gas milage, I seem to be getting bad milage, I used to get like 400 to a tank, now I just filled up like, 2 days ago, Im about at 1/2 a tank, ( I have been pushing her a little more than shes used to, I have been influenced) But Im at 1/2 tank, and Ive gone like 100 miles, thats a joke, whats the deal here?

 

O2 sensor can definately cause low gas milage, but it isn't the only thing. I thought that was it in my case and changed it, now I am still getting around the same as I used to, which is like 11 mpg. I will be lucky to reach 200 miles on a full tank. Fuel filter, sparks, distributor cap, rotor... etc.. Basic tune up things can cause low gas milage. I have replaced most of them and it still sucks ***. My next thing will be to check my distributor cap, rotor, replace wires and then if it still drinks gas I'll go to Nissan and have them run a diagnosis test when they hook it up to a computer. Everyone suggests that they WILL find the problem. Before replacing the o2 sensor make certain that is your problem.

 

Yeah the o2 sensor for the 90' SE (the VG motor) is like 100 bucks cheapest one i can find..i did all the tests i could to make sure mine was bad and turns out it is..but im not getting that bad gas milage i dont think.

 

Did you unplug it and then drive? Try to mention all of the things I should look for when I do that. Thanks.

 

i tried the unplug technique...i checked the signal with a voltmeter and a oscilliscope(sp?) too. all pointed to a bad 02 to test with a voltmeter u check voltage at the white wire from the 02 sensor with it plugged in and car warmed up. voltage should change from like .1 to 1 volt
mine was stuck at .2 or so...

 

I think Im losing it, now it looks much better, I think the first half always goes so fast, but my man brought sumthin to my attention, hes like stop pushing on the gas pedal in the morning ( I do that thinking Im getting the fuel up in my lines or sumthin, I think either my starter or fuel injector is going, I know its one or the other) I do stupid things sometimes, well I stopped pressing the gas, and I think its getting better, he he, boy I feel dumb.

 

Yeah if you were pumping the gas pedal while starting the car...thats not good fuel injected cars like ours are ment to start w/o pressing the gas.