Yeah, I'm getting a whopping 14 miles to the gallon, and thats with feathering the gas pedal! Now granted this is 95% city driving, but 14mpg is Ford Expedition territory.

This might be a result of my WSP Y-pipe install, somehow the o2 sensor got jacked up and now the cars running really rich.

Is there an easy way to tell if,

A)your running rich?
B)the o2 sensor is bad?
C)the MAF is bad?

What chain mechanic type places (i.e. Pep Boys, Midas, etc.) do free diagnostics? If it IS the o2 sensor, how hard is that to replace on my own?

Oh, by the way my car smells of fuel and there seem to be some magically appearing puddles on the pavement underneath my spare tire that don't evaporate so it can't be gas.

THANKS FOR LISTENING!

 

goto Pepoys and buy a Haynes or Chiltons manual...the diagnostic procedure is in there, will tell if rich and also if a sensor might be bad. Replacing the 02 sensor is easy if you have a jack and stands. I know Pep Boys does "free" diagnostics, but not sure if they run ECU codes(on OBDI imports at least).

 

Our 97 5.0 explorer gets 17mpg on average and 9-10mpg in the city. Why not check the o2 sensor in diagnostic mode II?

 

I feel you. My piece of crap is doing the same thing. I just spent massive amounts of money to fix my exhaust studs, replace my leaking y-pipe, complete tune up, pull and clean my injectors, 02 sensor, and some other mechanical problems. And I am still getting 14 mpg. I have said it before, I will say it again. SCREW THIS STUPID SLOW VG AUTO. AAAARRRGGGHHHH

 

gt out of the city for a few days and drive a tank or two of gas on the highway.. I've found that when I constantly drive in the city, it'll get down to 14-15mpg.. then I go for a nice loong weekend trip on the highway and I'm back up to 30mpg on the highways.. when I get back to town, my mileage hangs around 22-23 for a while, then drops back down into the teens..

most of it is due to my driving though, so I can't blame the car.. and guess what?
186k miles and ORIGINAL O2 sensor.

 

Do you think you could duplicate this by reseting the ECU?

 

wow, thats bad ... is it stop and go traffic (which is how most city driving is)

 

check the fuel lines, mine did the same thing, it's getting about +2-3mi to the gallon, since before there was a leak in the gas line, and the "exhaust" overflow..

 

Bad gas milage for a 5-speed usually means only one thing if all your sensors have been replaced.

BAD VTCS or slightly malfunctioning ones aka why I had bad MPG!

Jared

 

14mpg maxima, thats sounds about right.... when your stomping on it

na, thats Durango Territory, Expeditions get worse.
I've been getting pretty good with my Durango, but Arco is being really nice to the wallet right now... 87 octane for $1.25 a gallon.
$24.25 to fill her up. was going for $24 but missed it by a cent and knew they would give me $0.99 back

also check your cat. sometimes it can get clogged and that can cause it as well. the easiest way to see if that happens is if you notice a pretty good sized dent in performance or just feel of the engines response.

OBD II readers are sooo friendly for this. Its just too bad 3rd gens are before OBD II's time.
MrGone

 

I am just curious, but I am having my y-pipe replaced with another stock y-pipe that I got, was your y-pipe making the "gravel and pieces of metal jumping around everytime you step on the pedal" soound? I am replacing mine on the 18th and I am so excited to get rid of that awful noise. Yeeeeeeaaa!!!!!!

 

Most of my driving consists of 4 miles to school and back, never really anything over 5-10 miles. I never really go over 2.5 rpm, but I still dont really get too hot of gas mileage. I figure its just the short commutes, because on the highway, I usally get around 400 to the tank. I'll run a diagnostic tomorrow though

 

 

If it smells like fuel, could the injectors be bad? Also, if that puddle of gas is big enough it won't evaporate for a little bit. To find out if it actually is gas, move your maxima some distance from the puddle and get a match...

 

damm klown 400 a tank is sweet, i average about 315 on 15 gallons.
I drive all types everyday about 50/50 city and hwy. And I only use super 92 octane.

 

Gas smell is pretty strong, I wouldnt reccomend lighting it ANYWHERE near my max.


My MPG sucks too, I'm gonna try resetting the ECU and manually adjustding the TPS so that it falls closer to the FSM values. See what happens/.

 

My parents have a grand cherokee 5.2 V-8, and it gets 13.2 in city/highway mix. I'm sure an expedition would be worse yet, they weigh about half a ton more than the G. cherokee. So you're not doin that bad.