Poor Gas Mileage

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qx4dude
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Hey Guys

Please see my question at the bottom of thread! Thanks!
Modified by qx4dude at 8:55 AM 4/7/2010


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Freyspath
Posts: 104
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Car: 2003 Nissan Pathfinder LE

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Well if you got a code from a bad 02 sensor then chances are its bad needing replacement. You might have cleared the code, but the problem you'll run into is that it might not be sending the correct information to the computer (ECU).

I would replace that and then reset your ECU, (unplug the battery for 15-20min), and see what results you gain.

ALSO, another thing that kills mpg is having the transfercase on AUTO. Keep it to 2wd when you can.

I get about 260mi per tank when I drive in 2wd..Then again 40% of my driving is highway.

qx4dude
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Hey thanks for the help. Ya I figured it was most likely the o2 sensor. I leave it in2wd all the time of the roads arnt slippery.

The sensors are about 140 bucks. Do you think it's worth it to do the other pre cat o2 sensor as well? Do they both handle the fuel/air ratio?

Thanks again!

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Vaders R33
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96 Pathfinder SE

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the front O2 is for fuel mixture the rear ones deal with catylitic converter health. Just fronts for fuel milage. I am currently looking for the same problem.96 pathfinder 5sp 16 mpg 100% on the interstate 70-75mph

Buzzman
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qx4dude wrote:My truck (02 qx4).All my driving is city driving and I'm only getting about 320km a tank.
Hate to say it, but it's winter, plus you say it's all city driving, so 320Kms is not out of the ordinary. Also, if you run AWD or 4WD, you will notice a drop in gas mileage.I'm in Ottawa, and I'm lucky to hit 350Kms on a tank. That's usually only if I hit the freeway a few times. It gets better in the summer.

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Freyspath
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Car: 2003 Nissan Pathfinder LE

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Whats the avg for these cars outta curiosity? If I changed out my O2 sensors would my 15-16 mpg change much? if so what mpgs would I see come out of that car

tbsbiker2
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Car: 2001 SE Pathfinder

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I do mostly all city driving and I'm lucky to top 12-13 MPG around town. I'm not doing jack rabbit starts but I'm also not keeping it under 2K RPM. On the HWY I see 17-19 though. I'd love to see 15 mpg on the in town.

krisscat19
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Joined: Sat Feb 13, 2010 8:56 am
Car: 2000 Pathfinder SE

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I have a 2000 Pathfinder SE, (92,000 miles) and am trying to find out why all of a sudden I'm getting almost 50 miles less per tank of gas. My mechanic replaced the air and fuel filters and performed a fuel induction. No change. This problem started before winter so I don't think it's related to weather. Is the O2 sensor something I should have him check out? Is there anything else that could be causing the poor gas mileage?

Thanks! Kris

jjraymon
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Joined: Sun Mar 07, 2010 7:52 pm
Car: 2001 Nissan Pathfinder LE

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same here. my 2001 pathfinder with 65,000 miles all of a sudden went from getting a consistent 20 mpg about 100 miles per quarter tank to almost 10-12. recently i have had to replace my MAF and also my two rear O2 sensors due to codes "SES" light. i almost always keep it in 2wd and regularly check my gas mileage. I used to have to make 1000 mile trips every couple of months so i got accustomed to my gas mileage. after changing these parts with standard nissan parts my gas is literally draining out of my tank. Its not throwing any codes so i dont know what to fix next...neither do the mechanics!!

recently i have unplugged my battery for 12 hours in hopes of resetting my computer and any bad information it may have been sending my fuel injectors...any other ideas??

nbf6165
Posts: 25
Joined: Tue Aug 25, 2009 1:08 pm
Car: 2003 Pathfinder SE

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Mines down about 50 miles over the whole tank as well. I've had a couple mechanics tell me that the ethanol that has been added in the state of Georgia has had a big impact on fuel mileage.

Does an 02 sensor "wear out/down" or is it a working or not working type of thing? I've got no codes or anything feeling outside the norm.

Ordncebob
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Joined: Wed Dec 30, 2009 8:39 am
Car: 2006 Pathfinder SE

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I've had similar problems with some of my previous vehicles. The older they get and the more miles we rack up on them, the dirtier the injectors, throttle bodies, etc, get. I use a can of BG 44K fuel injection cleaner (about $20/can) every 30K miles and it does make a difference. Cleans out the entire fuels system and a little on the intake valves. Consequently, the exhaust is registering a more accurate reading in the O2 sensors which, in turn, adjust the ECU's intake parameters, etc.

Not a tech whiz on Nissans, so this is the best I can offer from personal experience. Anyone else with actual mechanical expertise on these vehicles will probably know more. I trust "most" mechanics, but I've heard the "....it's the gas" excuses as well as "maybe you need a complete fuel injection cleaning - we have a machine that'll do that for only $140"....because most cleaning machines and other service equipment require the customer to stuff $$$$ into them before they work, right?

Good luck.

krisscat19
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Car: 2000 Pathfinder SE

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I've had a BG fuel induction service and my mechanic found a defective coolant thermo-switch in the throttle body, but he didn't think that would have an affect on the fuel and he was right. I'm still getting poor gas mileage.

Did unplugging the battery work for you? Did it reset the computer and show any errors?

phatswinn
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Joined: Sun Feb 10, 2008 7:44 am

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You will see a drop in 3-6 mpg in the winter months between October and April because they use a "winter mix" gas to improve emissions with the colder weather (colder air is more dense therefore more fuel is being burned, so in turn the government implemented a strategy to lessen the actual fuel consumption during the winter months by using oxygen enriched gasoline, which is "beneficial" to the environment but at the same time kills gas mileage and you wind up paying for air in the process, also if your favorite gas station has turned to using a ethanol enriched gasoline for the green house b.s. that will come into factor also. this is part of the reason you will see such a large jump in mpg once spring comes around out of nowhere.

EDIT: the bad o2 sensor code will come up sparingly until you change it. you can get a universal sensor from most parts retailers for about $15 and it works just fine if you're OK with doing some minor electrical work.

QX4ME
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For the last tank I tried to keep RPM around 2000 when starting from a stop. I don't believe I got 19.5 MPG for the first time, and it was 100% city drive. Normally for cith drive I only get ~ 15 MPG average. My 02 QX4 4WD has 73000 miles and has no mods at all.

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Pwnin O'Brien
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QX4ME wrote:For the last tank I tried to keep RPM around 2000 when starting from a stop. I don't believe I got 19.5 MPG for the first time, and it was 100% city drive. Normally for cith drive I only get ~ 15 MPG average. My 02 QX4 4WD has 73000 miles and has no mods at all.
This post is so conflicting it doesn't make sense. So you got 19.5MPG just by keeping the engine under 2000RPM's starting from a stop?

QX4ME
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Yes. Due to the traffic conditions sometime the RPM was a little above 2000 RPM. The gas was from Costco, grade 87. I will try a few more tanks just to verify. A few months after I bought it new, I drove nearly 100% highway about 200 plus miles, I got a bit below 19 MPG, with one passenger in the car.

ugharin
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Car: 2000 QX4; 2002 QX4

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Hmm..interesting..I thought one would get the best gas mileage with a consistent rpm and that too around 22, 2300. 19.5 mpg sounds way too much even if keeping the rpm under 2k for city driving works favorably. I just filled my tank and will give this shot and see what I get. I otherwise got around 300 miles for a tank with around 40% of hwy driving when I once checked.

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RyanEvh
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Last time I filled up I got 460 kilometres before the gas light came on, which is better than when I first got my truck.

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Innovazn
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SURPRISE!! YOU DRIVE AN SUV!!!

qx4dude
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What other parts or mods could be done to improve gas mileage.

I once had an 02 sensor code pop up, but i erased the code, and unpluged the battery for a while and it has been 2 months and has not come back on.

I have done,

spark plugsair filterfuel filterregular oil changescorrect tire pressure (20% tread remaining)Always premium gasInjector cleaner from time to timeIntake resonator delete

The truck runs and drives smooth, starts perfect everytime. I dont drive it hard at all keeping the rpms under 3000 when exellerating. Pretty much all of my driving is around the city. I am getting some where around 300-350km a tank. Does this sound normal? Any other areas I could look into to impoving the km per tank?

Also does keeping the climate controll on "Econ" Make a big difference? I usually use the setting thats on half windows half feet.

Thanks again everyone!

Modified by qx4dude at 9:04 AM 4/7/2010
Modified by qx4dude at 9:11 AM 4/7/2010

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KyooX4
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In my experience, using 'ECON'/the fan over 'AUTO'/A-C has given an extra 1-2 mpg.I doubt fan speed or which fans are blowing have any impact.

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JonathanPrem
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If your driving city 300-350km is common man. You cant get better then that unless you drive like a granny. Most i got it like 375 before the light but i got a bad torque converter and death jerk at 80km+

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Empty V
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Innovazn wrote:SURPRISE!! YOU DRIVE AN SUV!!!
Thanks for clearing that up caps man. You're probably just too excited from dreaming about your blue LED washer nozzles.

Billy
Modified by Empty V at 12:18 PM 4/8/2010

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Innovazn
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Empty V wrote:
Thanks for clearing that up caps man. You're probably just too excited from dreaming about your blue LED washer nozzles.

Billy

Modified by Empty V at 12:18 PM 4/8/2010
i dont get it

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Empty V
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Innovazn wrote:
i dont get it
It's probably the use of punctuation and capital letters that's throwing you off. How's this: thanx for clering that up caps mang yer prolly just too exited from dreeming about your blue led wersher noseless

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Innovazn
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Empty V wrote:
It's probably the use of punctuation and capital letters that's throwing you off. How's this: thanx for clering that up caps mang yer prolly just too exited from dreeming about your blue led wersher noseless
definately didnt get it....

as for the punctuation,

sorry mister billy, please dont fail me in english...

its the internet... who cares?

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Empty V
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Innovazn wrote:
definately didnt get it....

as for the punctuation,

sorry mister billy, please dont fail me in english...

its the internet... who cares?
Who cares? You should! If you want people to understand what you're trying to convey then do it properly. The reason why we have a dictionary, punctuation, and grammar is because without it written language does not work. It seems that most of the retards your age did not pickup this up in school, or are just too lazy to hit the shift key. Lack of writing skills is also a sign of being unintelligible. You want to look ignorant then by all means.

In a perfect world you would be thinking about what's written above and apply it. But chances are you'll just come back with an idiotic reply like: "i dun need to no no english" or "im from canadia and we dont speak english in canadia we speak canadadian"
Modified by Empty V at 4:08 PM 4/9/2010

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Innovazn
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White 2002 Nissan Pathfinder LE - SOLD (blew the engine)
Location: Burnaby B.C. Canada

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Empty V wrote:
Who cares? You should! If you want people to understand what you're trying to convey then do it properly. The reason why we have a dictionary, punctuation, and grammar is because without it written language does not work. It seems that most of the retards your age did not pickup this up in school, or are just too lazy to hit the shift key. Lack of writing skills is also a sign of being unintelligible. You want to look ignorant then by all means.

In a perfect world you would be thinking about what's written above and apply it. But chances are you'll just come back with an idiotic reply like: "i dun need to no no english" or "im from canadia and we dont speak english in canadia we speak canadadian"

Modified by Empty V at 4:08 PM 4/9/2010
seems like youre doing a fine job understanding an unintelligible language then :S. if you want i can use my native language and draw f***ing pictures. whats your issue?

side note :: Don't know why you got such a hard on for me and try to slam whatever you can possibly find at me. I'll say this now, the information you have put into this forum as well as the write ups = A+, but kindly stop being a **** and let me throw as much cheddar, parmesan, mozzarella, monteray jack and what ever other cheese I can find at my own car without you breathing down my neck about it.

You got your car, I got mine, you dont have to see it on the road and I never asked you to stare at it. If you're willing to answer my questions I post without the sarcasm and 3 foot c*** slung over your shoulder, that's great. Otherwise kindly keep your comments to yourself and rage about it with your hands off the keyboard.
Modified by Innovazn at 5:19 PM 4/9/2010

Lillite
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Car: 99 QX4

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I've been getting about 20 mpg for the last 200,000 miles on my 99 QX 4. Ever since I did a tune up, my mileage has dropped about 25%. No codes. Yes I'm running 10% ethonal. Not by choice and I had noticed a little better mileage when I can find clean fuel but, this drop has me scratching my head.

Lillite
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Joined: Thu Dec 29, 2016 8:04 am
Car: 99 QX4

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FYI, milage has improved. Run only premium with cleaning additives. Changed the intake boot that was cracked. Changed thermostat, cleaned injectors and throttle body. When I get straight gas vs ethonal, milage is back up to about 20-22. Suspect now that vendors are not selling consistent ethonal mixes.


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