ive noticed in the past 2 months my gas mileage dropped horribly. I used to avg 400-420 miles on a tank now about 310-330. I noticed this after i made my ghetto intake, i juss took teh bottom piece of and ziptied the orginal filter to the top of box. After i noticed the difference, i put it back the way it is factory. But still nothing . current miles on the car is about 173,000. The plugs n fuel filter was changed about 50,000 miles ago? any ideas, i miss my old gas mileage, with the gas prices these days.

 

Check codes? Possible bad KS.

 

my SE light never went off, will it still give of codes??

 

what about fuel injection cleaning? plus you car has high mileage dont compare it with camry.

 

have you driven it enough with the stock box back on? the computer may need to adjust again.

 

i understand the car is hi mileage, but there is got to be a reason why the gas mileage drops 100 miles.

yes i drove over a month with the stock setup.

im thinking about seafoaming the car? just seeing what you guys think it can be. maybe ****ty fuel filter?

 

The fuel filter is overdue for replacement. It should be replaced every 30k.

You haven't replaced the plugs for 50K. What kinds of plugs did you use?

If they are NGK coppers, they are long overdue for replacement.

I wonder what shape your knock sensor is in.

 

Replace fuel filter, and yes, the KS code will be present without the CEL being on.

 

You used to get 400 to a tank! I only get about 250-275 and I use Premium

 

Hell my foot has always been to heave for that kinda mileage...Ive never even been close to 400,but I havent been on a full tank of highway miles with it yet,driving to Key West the end of this month so maybe all highway but as for now Im in that 275 range also.

 

Could it just be thats its COLD !!! Warm up Kills gas mileage man. Dont expect any miracles in the winter

-matt

 

its not because its cold, it started doing it when it was still warm. The decrease in gas mileage was sudden not over time....

my air filter is dirty so im gonna replace it... see if that helps than prolly plugs and fuel filter, and check if the KS is giving any codes.

i think tis my air filter, its not a K&N its a basic one, and it was exposed wide open for a bit and it was kinda dirty than. Im gonna do the changes and give u the update...

for u guys getting 275 on a tank.... i feel bad =[ ..... with my heavy foot it got 400 on a tank.... on a trip with all hiway dirving it went up to 480-490 miles on a tank

 

A tank can have many different meanings to people. A tank to me is to the 1/4 hatch mark which is about 12 to 13 gallons. Some people almost run the tank dry and fill up.

A true test is get your Mileage per gallon then report back

 

okay i usally run the tank low.....
fill ups for me r 16.5-17.5 gallons.
i like to ride the gas light until it stop flashing, and stays alwasy lit than i kno i deff need gas.

used to be:
fill ups avg about 24-25mpg
at 3/4 full i would drive 140 miles
at 1/2 full i would be 225-235 range
at 1/4 full i would be 330-350 range
when time to fill up in the 400's

current:
my last fill up (i ogt the recpit on me) avg 19 mpg
at 3/4 full i would drive 100 miles
at 1/2 full i would drive 170's miles
at 3/4 full i would drive 280's miles
when time to fill up 320-330 range

 

Man, if you every figure this out, let me know. I have virtually the same problem (except I didn't mod anything). I am right about 22mpg, where I used to be in the 25-26 range. I just replaced the K.S. so I'll give that a tank and see if it improves at all and report back. Next on the list if that doesn't work is plugs, then fuel filter.

 

I don't know how any of you guys get such great gas mileage. I have done almost everything to my engine, plugs,fuel filter,air filter,cleaned IACV,cleaned throttle body and I went from 200 miles per tank [16 gallons] to 230 miles.....wow! I was at 150 at the 1/2 tank mark and was like wow! I might get 300 miles? Nope, the other 1/2 tank just poured out for a whopping 80 miles. BTW my rpms never went past 3000 as i tried to see the most i could get out of a full tank. I think i'm averaging a huge 15-17 mpg....wooot!

 

How are your 02 sensors ?? Your a/f while cruzing under light throttle is regulated by your 02 sensors. If they are functioning properly, then your mileage will suffer. Ive gone from 27mpg before being boosted to about 24 around town and highway with boost, to the worst of 20-22 if I boost alot.

-matt

 

Wow! Thats pretty good. I have no codes right now. I had a rear 02 that i replaced but other then that no codes, not saying they cant be bad though.

 

Did you guys like disable a couple of cylinders or something??? I keep rpms under 2k and only get like 23mpg.... If I go all out it becomes like 17-18mpg.

 

I replaced my knock sensor and I still get bad mileage. I guess I will try and replace the spark plugs and the fuel filter. What is the full capacity of the gas tank?

 

yeah my gas mileage has been the $hits lately. Air filter, plugs, fuel filter are all new, within 5000km. I have a can of BG 44K in the tank right now, so after that tank is done hopefully ill see some improvement. Also my bank 1 02 sensor, the one on the ypipe is starting to go, hasnt thrown a code yet, but me and 2 of my technician freinds are suspecting it is, and my rear 02 is gone. My last tank of gas i got 240 miles to a tank, and i didnt even drive it that hard. Usually i can get around 320 miles to a tank.

 

Do the O2 sensors have a tendency to be bad even if they don't throw an error?

 

Some of you guys get REALLY bad mileage, wow. I was disappointed when mine dropped to 25mpg with the cold weather setting in. This thread reminded me though, it's about time I change my fuel filter...

In my experience they do throw a code, though it may take a while before it actually shows up.

 

Ok, thanks.

I have been ridding with my new knock sensor. Can't say my mileage has increased. Might be looking to do the plugs this weekend. If not that, then back to the drawing board. I have always gotten around 25mpg, but the 21-22mpg is driving me crazy! They only time i get that bad is mid summer with constant A/C and driving all city...