the horrible gas milage my 04 is getting

[ronsta]

Ok so how many O2 sensors do the 4th Gen v6 have?

 

[Belovian]

well if you have a faulty left side downstream, I would guess 4.


Jess

 

[ronsta]

well if you have a faulty left side downstream, I would guess 4.


Jess

I don't know if I have a faulty anything, just wanna change all of them to rule it out!

 

[MICA4R]

Jack up the front of your 4R and give the wheels a spin. In 2WD they should be 100% independent. If the front diff actuator is stuck then you are probably getting a lot of rolling resistance. Could be part of the problem?

 

[2004TR4-SR5]

hey gentlemen...since i am the op here i can't believe this is still circulating...i had posted a little while back about my O2 sensors and how did a ton of research on them...Belovian is totally correct and as weird as it seems...a faulty O2 WILL NOT always send a light...after learning a little bit on how to read my OBDII scanner with the live feed i had come to a conclusion its gotta be faulty pre cat O2's....now i have yet to replace them...sucks living pay check to pay check...although i am a 23 year old who works his ass off...once i do repair them...you fellas will see a post INSTANTLY..cause i would love to get this bullish!t fixed.

Have a good day/night!

 

[mean machine]

First off hi all, this will be seen by some as poor etiquette by some for a first post but here goes...

A lot of people mentioned O2 sensors, but I don't remember reading where anyone so far has tried it. As a certified auto tech for over 15 years, I can attest to the fact that poor performing or "Lazy" O2 sensors can affect gas millage. If anyone wants to do this, replace the two upstream sensors or pre-catalyst. those are the important ones. the sensors after the catalytic converter are there only as watchdog to monitor the converter and the other sensors.

As far as other reasons for seemingly sudden poor economy, tire pressure, wheel alignment, sticking brakes sticking u-joints and wheel bearings are possible causes. Living in the great white north We still have gas with no ethanol, I go to the U.S. quite often filling with E10 kills fuel economy by about 10%.

Lastly, for those living in colder climates, two things. First it is true that air air temp decreases density increases. this in turn means more fuel to keep optimal A/F ratios, it also means more power though so the losses aren't drastic. Secondly, when a vehicle is cold it operates in what is called "open Loop" mode. Before certain things are at a certain temperature (O2 Sensors mainly) the vehicle disregards certain readings and runs a preset fuel map. this is richer and helps warm up quicker. the colder it is the longer this process takes.

So, there it is, my first post here. I hope This helps a couple people out, that those getting poor millage can find a solution.

Jesse

Oh, yeah, E10, you are lucky when merely lowering gas mileage is all it does.:banana:

Called ethanol to make it sound like it it ain't alcohol that turns into water if it sits around too long.....



:toilet:

I would add that it is very important to keep fresh gas with E10, because it will seperate out, and do all sorts of other damage-including damaging carburetors (yeah I know yours has fuel injectors, but I do not know how well protected are the fuel lines and other parts leading up to the injectors).

What is worse, is the effect of the stuff on two stroke motors and fuel lines-even if fresh gas is all you use:sobbing:

 

[mean machine]

Some links to gas problems.

Personally, my guess is that if you use pure gasoline, such as racing gas, you would see a big MPG improvement.

I also wonder about the effect of this stuff on the O2 sensors.

Gas has gone crazy over the last ten years as to quality and price. I bought a turbo f250 in 1999 that used diesel. Price of diesel was 10 to 15 cents per gallon cheaper than regular gas (gas which was not overly polluted by alcohol at the time)


Now diesel is selling for 10 to 15 cents (or more at some stations) per gallon than PREMIUM Gas

And while I am not expert (except an intenet expert:shrug as to auto engines, I do know my two strokes, and the stuff is killer on motorcycle engines and boat motors. I know that I had problems with the stuff on the boat until I put a WATER SEPERATOR filter on the gas line. I frequently have to drain the WATER from it......way too often if you ask me.....

Now I wonder if that might be something to add to our 4runners...i know about the fuel filter already on the car, but it does not appear to seprate water as far as i can tell........my f250 had such a water seperator filter for the diesel that everytime I changed the oil, I drained the seperator....of much water......


Boat filters:
How to Install a Fuel Filter Separator in a Boat | eHow.com

Gander Mountain® > Fuel Filter/Water Separator - Boating > Fuel Systems > Fuel Filters :

Just wondering:sadwave:

other links about the problems:

http://www.toyota-4runner.org/4th-gen-t4rs/19308-ethanol-gasoline-mileage-improvement.html


http://www.toyota-4runner.org/5th-gen-t4rs/89717-beauty-pure-gas.html

http://www.toyota-4runner.org/4th-gen-t4rs/19850-ethanol-warnings-print.html

 

[ronsta]

Back to the O2 sensors issue, found Denso & Bosch. Anyone know the difference? Which one is a direct replacement?

according to Rockauto:

DENSO is OE style - means what?
BOSCH is OE Type - Exact Fit

 

[ClockWork]

Denso, brah.

 

[ronsta]

Denso, brah.

so denso is stock?

 

[MICA4R]

so denso is stock?

yes..

 

[ClockWork]

so denso is stock?

Little common sense. Denso is a Japanese brand that makes automotive components for the JDM. Bosch makes automotive components for the EDM.

Or Google

 

[ronsta]

Little common sense. Denso is a Japanese brand that makes automotive components for the JDM. Bosch makes automotive components for the EDM.

Or Google

Common sense, right.

 

[MT-4RUNNER]

when i was getting good mileage...my odo would read like almost 300 miles if not a little over 300 when i would fill up from a 1/4

I was getting the same a month ago, and now it seems it has gone down hill... Im questioning the tire balance and alignment.

 

[Whitebeauty]

I was getting the same a month ago, and now it seems it has gone down hill... Im questioning the tire balance and alignment.

Its funny i c this. To tell u the truth if we all wanted fuel saving vehicles im sure we would not have bought our vehicles... Of course with todays technology, our vehicles will just get worse n worse fuel mileage to the tank.. With my endeavours of power hunting, it has led me to some of our favorite n sweet corn oil...lol.. I used to get like 360 to 380 to the tank on pump 93. Now with the E85.. i get like 270 or so

 

[ronsta]

I was getting the same a month ago, and now it seems it has gone down hill... Im questioning the tire balance and alignment.

Wouldn't you feel it if it was tire balance/alignment?

Its funny i c this. To tell u the truth if we all wanted fuel saving vehicles im sure we would not have bought our vehicles... Of course with todays technology, our vehicles will just get worse n worse fuel mileage to the tank.. With my endeavours of power hunting, it has led me to some of our favorite n sweet corn oil...lol.. I used to get like 360 to 380 to the tank on pump 93. Now with the E85.. i get like 270 or so

I remember getting 400+ on the range computer, the specs on edmunds even says so too! It's probably not a sole factor merely a combination of things including but not limited to the ethanol in gas, bad/old O2 sensors, bad/old MAF sensors, drivetrain lubrication, spark plugs etc...

but then again funny how my moms car, an '04 rav 4wd still runs the same since when brand new and only thing done on it are oil changes!

 

[MikeInNH]

I have a hard time believing that the O2 sensor is going to cause a problem. If the O2 sensor is putting out bad data.....it should trigger an alarm in the ECU....and post a code. There's an acceptable range of values an O2 sensor can report...and as long as it's in that range...gas mileage shouldn't be effected much.

There are also tests that can be run to determine if the O2 sensor is performing correctly.

 

[phqduphead]

When I notice my mpg starting to get below 15 I unplug the negative of the battery which I'm guessing resets the cpu on the car and then I'm getting around 17 again. V8 255/75/17

 

[MT-4RUNNER]

Wouldn't you feel it if it was tire balance/alignment?

Im just saying this because I was messing around with the suspension about a month or 2 ago and it seems it could be possibly from this.

 

[Whitebeauty]

Im just saying this because I was messing around with the suspension about a month or 2 ago and it seems it could be possibly from this.

Thats with out a doubt. wheel size and ride height and all types of other things can affect..:lookout: