mrfxho

iTrader: (1)

So I was thinking....

1. 4 brand new tires
2. 6 new NGK Iridium Spark Plugs
3. Abt 38lbs of air in the tires
4. Car isnt pulling ( was alligned when had new tires installed)
5. fresh oil change
6. New valve cover gasket ( no more crazy oil leak)
7. Running E93 gas (premium)
8. New Berk Short Ram Intake
9. Clean MAF and TB....

And my gas mileage still sucks. Im getting about 220 miles to a FULL tank

Next thing I was thinking, I might have bad O2 sensors. Ive read a little on here and I know with having bad O2 sensors you will loose out on gas mileage. Now I dont know how to determine that I have bad O2 sensors, so i went out to my car and snapped a couple pics with hoping you orgers can help me out, considering I was looking at the prices of purchasing new O2 sensor from Bosch @ $130 a pop for each one.

Heres the 1st front O2 Sensor (behind the radiater)


Now heres the 2nd rear of the motor O2 sensor (close to the firewall)



Last one, under the car. 3rd O2 Sensor


Dont mind the oil. I just recently fixed a bad oil leak about 3 weeks ago and tried cleaning everything off the engine and from the undercaraige with Purple Power Degreaser Cleaner, but its a bit** to get off especially after it has been leaking for about 5 months, so I just decided to let it burn/ fall off on its own.

So any suggestion after looking at the pics of the O2 sensors would be greatly appreciated. As well anything else you guys think i can do to improve my gas mileage??

Thks,
Luis

VQP0WER

You will almost certainly get a check engine light if a O2 sensor is bad. This is one of the main things the computer looks for. If you don't have a CEL I highly doubt its your O2's.

Pictures also will not tell us anything since the heating element/sensor is inside the bung hole in the exhaust piping.

Alot depends on your driving habits. When I had my Max, I got about 260-270 to a tank, and that was about 75% HW and 25% CITY. I had a heavy foot.

You also might want to lower your PSI a little in your tires. We are only suppoed to have something like 32 PSI in each tire.

phatboislim

iTrader: (27)

i get at least 330 miles on a tank regardless...i avg around 350-370 miles to a tank, maxing out at just over 400 miles a tank

ColdRain

These are very good miles. I'm getting about 260-280 now with all city driving. To OP, I guess few other things to check would be air filter, extra weight, Anything wrong with exhaust backpressure?

phatboislim

iTrader: (27)

as far as weight...i can chime in on that too...ive been riding around in my car with a crate full of BS, a jack, tools in the trunk. possibly air filter i agree with or maybe a clogged cat convertor. is your car doing anything out of the norm? like VQ said a bad o2 sensor warrants a SES light, and you said you dont have any so...

sud123

These are the milages I get on my 2000 Max SE all stock, if this of any help....

All city: 300miles/tank
All Highway: 390miles/tank

mrfxho

iTrader: (1)

Well now since you mention it, there was a time about 6 months that my service engine soon light came on so I thought it was because I needed a oil change (i was over by almost 2000 miles) but once I had the oil change done my light was still on for 3 days, so I went to the autozone to use there computer and the car was giving me a bank 1 and bank 2 error messege. So I looked into it and after 2 days the light dissapeared and when I went back tio try the computer again, it wasnt showing any error codes. Don't know if this is normal or if this would help you guys in helping me out since I'm not to bright with mechanics unless its with jet skis lol

phatboislim

iTrader: (27)

i have periods when my SES light goes off and i think it magically fixed itself but voila it comes back..just wait for it to come back on...but yea...sounds like o2 sensor maybe a PART of your problem

mrfxho

iTrader: (1)

Ok so im really leaning to saving up a lil money and purchasing and purchasing all new 4 O2 sensors.

Where would be the best/cheapest to buy these O2 sensor without it costing me a arm and a leg.

I want it to be of good quality as well but not extremely expensive. Those who have replaced there O2 sensors, whcih did you guys decided to use?

One more thing, is it necessary to replace all four O2 sensors if I am getting bad gas mileage or are there certain one that I can replace which would helop me in this field, like just replacing each one in the headers?

Thks,
Luis

dustey

iTrader: (1)

Maybe you mentioned it previous, but how many miles are on your car? O2 sensors are said to be a 100,000 mile replacement part. I am assuming you are at least at that. It certainly wouldn't hurt to replace the O2 sensors if they are original. I found better prices on either eBay or RockAuto.com.

What is E93? Is that an Ethanol blend? I try to avoid that, if possible.

Also, pay attention to those CEL's and what code that AutoZone tells you they are. Just write down the codes (It will be in a PXXXX format...) and then come here and do a search for it. That may help...

I think I get pretty bad gas mileage, IMO. I couldn't tell you the last time I got over 20mpg, but I do drive all city. I don't calculate it out exactly when I do simple math and I know its not going to be 20mpg.

Saying "I get XXX miles on a tank" isn't really helpful as one person may drive on a tank of gas until the Low Fuel light comes on which means there are still a few gallons in the tank and others may run it and coast into the gas station on fumes. Actual MPG numbers are the best way to compare apples to apples.

VQP0WER

You only need to replace the two primary O2's since the secondaries don't do anything regarding air/fuel if you wanted.

mahanddeem

I recieved my 2 front O2 sensors , Denso OE style ..they were 81$ each...Good price in my opinion from rockauto.com

2000_MAXIMA_KING

iTrader: (30)

I only get about 250 gallons to a tank at most, No CEL and this is the second 5th gen I had and same ish. I'm curious to see your solution to this problem.

Btw all city miles for me.

yankeefan13

I just changed my oxygen sensor it had a service light on though.. It was p0135 but after it was changed my mpg got better.

mrfxho

iTrader: (1)

yea, forgot to mention that I drive 85% city and 15% highway (rare bc sometimes I go a entire tank without hitting the highway) but I go into the gas station when my gas light turns on and my speedo is blinking saying theres --- MPG left.

My life pretty much is going to work (15-18 min away from home and abt 9 miles away), going to my girls house every other night (7 mins away and abt 4 miles away), sis house @least once a week ( 2 mins away and abt 1 1/2 mile) and occasionally on the weekend me and my girl go out or to a friends house and thats abt my weekly travel. So LOTS of city driving. Maxxed I have ever got on a full tank will be 230-240 and thats driving like a grandpa without stepping on it.

So which would be the only 2 O2 sensors I would have to replace mahanddeem and yankeefan13?

VQPOWER, which are the primary two O2 sensors that you reccommend replacing?

Thks,
Luis

mahanddeem

Like the other knowledgeable people said here : the only 2 important O2 sensor are the front (or upstream) sensors , both of which are before the 2 pre-cats..Don't worry about the downstream ones cause they ONLY monitor the pre-cats function , and if they're bad you only get SES light.....I ordered mine from rockauto.com and they were Denso....Forget about eBay craps...

Love_00_Max

I will replace all 4 sensors if I had the money... BTW the "knowledgeble folks" don't know that O2 get lazy and may never thro a code. They last at best 100K and if u have 100K on them time to change. U will recover the cost over an yr with more MPG.

Check your coils too they may be faulty running the engine rich with all the richness (fuel) going downstream into the O2 and cats.

mrfxho

iTrader: (1)

can you guys post pics of which ones are which. bc I found this in a stciky thread

now i just need to know which one you guys are talking abt lol.

By the way, the car has 145xxx miles on it. My grandma gave me the car back in 2007 bc she said it was waisting too much gas for her and she was going to sell it but offered it to me first with only 80xxx miles on it for $4,000 since im family lol.

mrfxho

iTrader: (1)

Anyone?

mahanddeem

Bank 1 sensor 1
Bank 2 sensor 1

I bought these
DENSO Part # 2343113 OE Style
Front (Upstream) Right
Front (Upstream) Left

and yes....It's not always necessary to have SES if an O2 sensors is bad...

mrfxho

iTrader: (1)

thks brother. really appreciate it

mrfxho

iTrader: (1)

So just came from the Autozone and the computer pulled a error code P0011. Would this be because of bad O2 sensors?

Thks,
Luis

shdwonthsun

iTrader: (1)

google says camshaft position

mrfxho

iTrader: (1)

and would this affect bad gas mileage??

shdwonthsun

iTrader: (1)

i dont know the answer to this and i dont want to give you bad information, but im willing to guess that it could if it pulls timing or something.

that being said, you're gonna wanna look into that sooner rather than later.

i can however tell you that maximas are pretty bad in the city. its a lot of car to get moving every time you stop.

mahanddeem

start with simple to "more serious" things....

1.Reset and see if that code comes back or not
2.Check the fuel you use..(don't put less than 93 octane)
3.Check oil level periodically (does you car burn oil?)
4.Check for oil or vacuume leaks
5.Have the timing checked

Majestic Ken

iTrader: (5)

I have codes for bad 02's also, gonna save up and get all 4 done with me having 162k on a 03. drive 35-40 miles a day 4 days a week. not including weekend trips. if i take the car out of town i get about 460+. city is 385 on a full tank

kauaiwyatt

iTrader: (5)

the Walker brand sensors are $60-$80 here & work fine:
http://www.oxygensensors.com

BigLou55

iTrader: (6)

I do about 50/50 highway/city and I get 425miles on a full tank no mods i dont do the speed limit and its about time to get some new plugs

L_U_D_I_AMaxima

iTrader: (3)

WOW
I just picked up a 2000 se 5 speed in the summer with 166,xxx + , I do have a SES light for the post cat 02 sensor but my average per tank of gas is anywhere between 380 to 450 miles depending on how much I have to drive city... Man I was thinking I had a bad gas millage...

Maxident

I think Maximas just have crap mileage in town. I have an '02 GLE and only get between 15-17mpg average with almost all city driving. I measure my mileage by dividing miles driven between fill ups by gallons purchased.

VQP0WER

You must drive like grandma.

cabernet

Try Amazon for a low price. I bought the Bosch 15955 O2 sensor (for Calif. cars) for $58, no tax or shipping costs.

Eirik

iTrader: (2)

http://www.autohausaz.com/html/emiss...n_sensors.html

Sneaky Green

Try getting a new fuel filter and see if your cat is clogged after. I get between 240-280 at the most with 60% highway and 40% city and my car pulls codes every other week about to install my obx headers maybe they will help.

strainca

one of my o2 sensors is bad and ive also been having issues with gas mileage. havent gotten it fixed yet, but maybe that is my issue

grip1968

I get 420 miles in a full tank, All highway miles

njmaxseltd

iTrader: (19)

^^^This plus winter is killing your MPG.

Take the car on a good long trip and measure your MPG.

P0011 - Camshaft Position Sensor controls Fuel Injection Timing.
It's possible that's having an impact on your mileage.

berniek

There is a way to determine if an O2 sensor is working properly. Lightly clamp the wrench hex in a vise with the exhaust element pointing up. With a multimeter, determine which leadwire is the heater (low resistance to ground) and which is the sensor output (very high resistance or open circuit indication. Set the multimeter to the 2 volt range and connect the + lead to the sensor leadwire adn the - lead to ground (the sensor housing or vise). Heat the sensor element with a propane torch (Bernzomatic). Do not use an acetylene torch). The element can be heated to a dull red heat in a normally lighted room. As the flame is removed from the element, up to one volt will be generated as oxygen in the air gets to the hot element. You can play the flame back and forth over the sensor element and watch the voltage cycle between zero and one volt. The flame envelopes the sensor and prevents oxygen from getting to it. If this works, the sensor is good.

BernieK

Waxima

iTrader: (3)

Are you auto or 6-speed? That's some fantastic gas mileage.

I'm with the OP barely pulling 220 out of a tank with almost all highway driving and I think I'm going to look into replacing the two primary o2 sensors as well.