10 mpg

[04ebexpy]

i have an 04 with the 4.6 203k recent oil change new plugs and coils properly gapped no codes new air filter. It has been seafoamed like an induction treatment and I cut the muffler out because of a broken loose baffle and my gas mileage has improved since to between 10-11mpg. No codes

Any one have any thoughts or anything you can point me to. I’ve never seen mileage this bad in my opinion if it is normal let me know but it seems abnormal. No brake dragging either just redid all 4 wheels

 

[JExpedition07]

Clogged cats? Have you done fuel filter change?

 

[Habbibie]

You know it could be the driver lol I been ******** about how I get 7-8mpg on my expy for years... well my wife is been driving it for a week and shes reporting 14.4 mpg back and she constant uses the AC! I dont even know what an AC is

 

[R W Carpenter]

You know it could be the driver lol I been ******** about how I get 7-8mpg on my expy for years... well my wife is been driving it for a week and shes reporting 14.4 mpg back and she constant uses the AC! I dont even know what an AC is

It sounds to me like you have what is commonly known as leadfoot disease. Better get that checked my friend.

 

[John Christopher]

Habbibie is right. The way you drive has a lot to do with mileage. Try to avoid jack rabbit starts. Gently press the gas and get into the higher gears as soon as you can. Look ahead to see if the light is red and get off the gas coasting to a stop. Keep your tires at the recommended air pressure. Keep speed to a max of 65 mph. All of these things should improve your mileage.

After you completed the above floor the truck and have some fun with the gas you saved.

 

[BRIANGEE]

Put me down on the mechanical issue side of this thread. I liked JExpedition's comment but would also add looking at fuel trims and o2 data and possibly fuel pressure if that info takes you in that direction.

Seriously guys, does anyone lead foot an expedition? There is no return in doing so... The thing is a million pound slug.

 

[Dorzak]

Put me down on the mechanical issue side of this thread. I liked JExpedition's comment but would also add looking at fuel trims and o2 data and possibly fuel pressure if that info takes you in that direction.

Seriously guys, does anyone lead foot an expedition? There is no return in doing so... The thing is a million pound slug.

Let me introduce you to my big friend. The 3.5L Ecoboost can get up and go. Just saw the mpg thread in recent threads and jumped over. Oh, and when I got it the second trip odometer and MPG estimate had not been reset. It was at 19, daily driving I am at 15.8.

 

[04ebexpy]

Wife gets similar gas mileage so while it may be driving I’m kinda doubting it. I’ll have to look into the fuel filter I don’t remember. I got an o2 code not to long ago for the after cat o2 and my wife’s dad did run it for a while with a misfire so I maybe I have a clogged cat. Any sure fire ways to tell without cutting them out first?

Anyone with any other ideas

 

[Habbibie]

Wife gets similar gas mileage so while it may be driving I’m kinda doubting it. I’ll have to look into the fuel filter I don’t remember. I got an o2 code not to long ago for the after cat o2 and my wife’s dad did run it for a while with a misfire so I maybe I have a clogged cat. Any sure fire ways to tell without cutting them out first?

Anyone with any other ideas

Sounds like you're due for a tune up more than worrying about a clogged cat, when was the last time the spark plugs & the various filters replaced?

 

[JExpedition07]

You can run laquer thinner in the gas to help clean the cats if they are indeed clogged.

 

[04ebexpy]

I just did all the plugs properly gapped with all new coils and air filter and an induction service 1k miles ago

 

[BRIANGEE]

[QUOTE=

 

[1955moose]

Is it 2 or 4 wheel drive? A last year 4.6 2 wheel drive should be around 13-14 city, and 4 wheel drive around 11-12. Highway obviously jumps. My 2000 4 wheel drive gets 10 city, 15-16 highway. I have larger wheels 20 inch, which I hear Rob's some. Try what Brian said about having fuel trim checked, you might be running fat.

Sent from my N9131 using Tapatalk

 

[04ebexpy]

Yea it’s a two wheel drive and ok what is the best method to have my trims checked? All the normal simple stuff I’m fairly certain I’ve covered so it’s got me more than a bit confused.

 

[1955moose]

You need to go to a shop or maybe a friend that has a better scanner that can read what is called fuel trims. Any of the shops that use Snap on, Matco, Ford Approved or any better quality scanners can tell you. Sounds like you may need to have an experienced shop finish this job, nothing wrong there. These are tough Suvs to wrench on. Finding driveability issues tougher still. I've seen some of the best get stumped.

Sent from my N9131 using Tapatalk

 

[johnboneske]

Pull the front O2 sensor on the side that you think is clogged, and either install a pressure gauge or a hose of some sort start your Expy and feel for any air pressure. If there is more than 2 or 3 psi its clogged. CATS aren't suppose to have any pressure in them.

 

[04ebexpy]

That’s an interesting thought I will have to look into that when I have time

 

[1955moose]

Another way to see if all 4 cats are clear, get ahold of a digital temp gauge. Heat up your SUV, aim it at the entrance and exit of each cat, the temp should be 100-200 higher at exit side, towards rear of vehicle. If not you found you scalded [emoji250]!

Sent from my N9131 using Tapatalk

 

[04ebexpy]

I don’t have a temp gauge but I do have an obd reader and the torque app it registers fuel trims I just have to figure out how to read them

 

[BRIANGEE]

Search for 'Schroedingers box fuel trim' on YouTube. He has one of the best videos out there if you want to learn how to use fuel trims to help diagnose a lot of different problems.