Fuel Economy Question

[kalasend]

Hi All,

I just bought a '04 automatic. The fuel tank seems to be emptying too soon.

After purchase, I put in about 14 gallons(almost empty at the time), ran about 200 miles now and it's pointing at just above the lowest quarter mark (ie. about 4 marks up from bottom mark). At this rate(reasonably assuming that the gauge is linear), I predict that this tank cannot even go over 250 miles. 250 mi / 14 Gal = 17.86 mpg , and a least half of those miles are highway.

I plan to reset the ECU (battery down for > 10 mins) after this tank of fuel is done. Is there anything else I should be doing?

PS: This car's done some high miles in short time(83k / 3yrs), would that cause the oxygen sensors to defect sooner? In reality when should oxygen sensors be replaced?

Thanks in advance

[smooth1]

hello, and welcome to the LOC btw.

Yeah, I would do the ECU reset first. Also check the air intake.

If you had an O2 sensor issue it would probably be throwing up a cell by now. So I don't think that's it. You are running 91 min. octane yes?

Your the second person recently to say something about getting 17 mpg. I have an 05' and drive it hard and get 310-320 miles to a tank. ( right around 21-22 mpg)

The mileage on your car shouldn't have anything to do with it either. Although, based on mileage, and not time, you are due for a major tune. Do you know if that was done?