1 Gallon Of Gas

[OlegWasHere]

Looks like you have covered just about everything else that is easy to troubleshoot... this is where I would go next. Most muffler shops can do a new O2 sensors for you if you don't want to climb under there and do it yourself. I prefer to leave exhaust work to guys who do it every day, but that's me. I'd buy the new sensors online and bring them to the shop.

If I'm not mistaken, there are 2 oxygen sensors in the cat on your car. You need an O2 sensor socket, both new O2 sensors, PB Blaster and a little free time. It's not too difficult. Don't work on hot exhaust, either.

Other things to consider are vacuum leaks (ugh, just shoot yourself), fuel pressure regulator or a dirty EGR valve (if you have an automatic). Is the car running rich (black soot on the bumper over the tailpipe outlet)? When was the last time you changed the oil?



doug

nope nothing on the bumper or exhaust.
everything works perfectly besides the gas mileage being off.
ac works heat works.
no coolant leaks.
nothing.

so stupid question.
you say there are 2 o2 sensors.
are they the same sensor just two of them?
because i looked it up on autozone and they only have an upstream o2 sensor

 

[squarehead]

you say there are 2 o2 sensors.
are they the same sensor just two of them?
because i looked it up on autozone and they only have an upstream o2 sensor

I think it depends on the year and the specific engine. I think cars that have two O2 sensors, they are different sensors. I know there are two different ones on my car. YMMV.

 

[Cripton805]

nope nothing on the bumper or exhaust.
everything works perfectly besides the gas mileage being off.
ac works heat works.
no coolant leaks.
nothing.

so stupid question.
you say there are 2 o2 sensors.
are they the same sensor just two of them?
because i looked it up on autozone and they only have an upstream o2 sensor

OBD1 will have one sensor on the header.
OBD2 will have two sensors (post and pre CAT)

I would say the intake is a major problem with a lot of people. Everyone swaps out their intakes and fail to realize they need to be cleaned. :shock:

Clean stock intake is better than a dirty clogged aftermarket POS. lmao

 

[OlegWasHere]

i have a 95 se
so b18bi 0bd1
so one o2 sensor
how much does labor usually run for this.

everything on my car is stock besides wheels and k&n air filter.

 

[teg_your_it]

on avg, in the winter i've gotten 24mpg, summer 30mpg.

the most i've gotten was when i drove a 6hr road trip and calculation came out to be 33mpg, with one of the rear breaks dragging (seized caliper i think, but just gotten replaced) and a bunch of luggages. i can't believe it gotten that much with all that stuff. the rear looked slammed at that time. only mod was a rsi and full catback.

i think i can get 36-40mpg now on the freeway.

 

[Spyder Java]

One reason that you may also be getting bad gas mileage at the top half of your fuel tank is that you actually have more weight in the car, though it shouldnt be too noticable between the two halves...

 

[OlegWasHere]

One reason that you may also be getting bad gas mileage at the top half of your fuel tank is that you actually have more weight in the car, though it shouldnt be too noticable between the two halves...

you mean between times i drive the car?

95 percent of the time thats a no.
just myself and a backpack
114 piece tool set
a bottle of antifreeze
a bottle of windshield washer fluid
spare tire
nothing out of the normal heavy.

 

[squarehead]

No, I think he means the weight of the extra fuel in the car when it's full, but that is really minor, all things considered. A gallon of gas weighs about 8 pounds, so a full tank weights about 105 pounds, so a half tank is only 50 extra pounds. It's definitely not the source of 15 mpg loss, at any point in the tank.

I'm putting my money on the oxygen sensor.

 

[Prozon]

thats what im saying. before owning this i had a v6 chevy blazer and it got better gas mileage.
honestly im not complaing about it not having 400 miles a tank im just saying its odd that on 10 gallons i only get 175 miles but on one gallon i get over 35. what's up with that.

My previous daily drivers were a '98 Chevy 3/4 ton pickup, and a lifted '88 Ford F350. Both had V8's. Lol. I have a '98 Chevy Blazer as well, but something effed up on it so it's getting ridiculous gas mileage.

Its just weird to drive somewhere and not see the gauge move at all.

stop complaining guys

i got around 24ish city when my teg was stock


after the turbo build, bigger injectors, and tune......i get 17 mpg

That seems a little bit too low.. Boosted LS Gas Mileage
I think i'll have to look at your build thread. Lol.

Also Guys I have noticed that when you fill these up once you get to full and the pump will click as it is full, but u can continue to keep pumping for a bit. How much past the click is it safe to keep pumping? I usually go and extra $1.00-$1.50. I wanna find out how much mpg's are but I never know if Im fully full lol.

You should probably just go until the first click when calculating mileage. You could overfill your gas tank and have it shoot out all over your shoe. :lol:

 

[bu_bomb420]

thats what im saying. before owning this i had a v6 chevy blazer and it got better gas mileage.
honestly im not complaing about it not having 400 miles a tank im just saying its odd that on 10 gallons i only get 175 miles but on one gallon i get over 35. what's up with that.

you also gotta see it like this... gas weighs alot... try putting a backpack filled with stuff on your back and run... and then do the same with one thing in your hand.... lets see how much farther you can go with one of the two....

 

[squarehead]

you also gotta see it like this... gas weighs alot... try putting a backpack filled with stuff on your back and run... and then do the same with one thing in your hand.... lets see how much farther you can go with one of the two....

An average male passenger will weigh about 175 pounds—a full tank of gas weighs about 105 pounds. He's not getting ~15 mpg with 105 pounds of fuel in the tank. It's definitely NOT a weight issue.

 

[Spyder Java]

I didnt say that was his problem, just that it could explain a ~1 mpg loss when tank is full compared to when tank is almost E. Not a 15mpg change.

 

[Bear Scientist]

My driving is about 60/40 highway/city and i get 28 mpg on my '99 ls w/ 141k, I don't drive like a grandma, but i'm not racing from one stoplight to the next, either. The gauge DEFINITELY drops faster after the 1/2 mark, every car i've ever owned has been like that, though. There is no way in hell the weight of half a tank of gas is making any significant difference in your mileage, that's stupid. I think your next step is what everyone else is suggesting, new O2 sensor.

 

[camopaint0707]

topped out at 50 mpg on the highway

 

[nvuswhippz]

^ Prius??? I have noticed also when i fill my tank full it loves to suck the gas up until a little above half a tank and sit there for a good amount of time then once i passes a little below the half it flies to EMPTY!! just curious is this a gauge malfunction or what it has always been like this