My gas mileage has really gone to crap. I am getting a little over 11 miles to the gallon. No more than 250 a tank. A couple of months ago, I ran a can of seafoam through the vehicle, and then ended up having to change out a couple of plugs and coil packs. The engine still sounds like it is missing a little and is somewhat sluggish, but it is not throwing any codes. Any ideas on where to start on this one?
Thanks
Craig

 

Funny how the magical "Fix It All" Cure Seafoam is not such a quick fix it seems.

 

My truck has been getting the same kind of MPG. I havent added anything to the gas or anything. I think my IAC is dirty but would that cause MPG like that?

Maybe we can get something figured out. Best Ive had was 16mpg last fall. 2002 supercab.....

 

My gas mileage has gone from 11-12mpg to 14mpg since I removed my cats. Also, replaced my front O2 sensors a few days ago. I haven't run a full tank through the truck yet, but I've already gone over 200 miles and I'm on 1/2 a tank. If you think your cats might need replacing, you need to go aftermarket. The ford replacements are $1,100!!!!

 

I replaced the IAC at the same time I did the plugs and coil pack, so I am pretty sure it is not that. However the O2 sensors may be the place to start.
The truck has 70k on it. Im guessing I am probably due. Any other thoughts?

 

It wouldnt be a bad idea to change them, 70k is probably a pretty good life expectancy for them.

What about the fuel and air filter? How long since they were changed?

 

Fuel filter was 5k miles ago
Air filter was 10k ago when I switched it to a K&N

 

I don't know where your located, phishman but winter gasoline mix can reduce the mpg.

http://www.startribune.com/131/story/151177.html

 

I threw a can of BG44K in and
now Im up to 300 a tank. Im doing the O2 sensors this weekend, maybe I can get 350 whoooooooooeoeeeeeee

 

Chester what do you call the cat? Where are the O2 sensors located and the IAC?

 

CATalytic converter. It's just a common name for that. It is a device that is installed inline your exhaust system. Its purpose is to reduce harmful emissions. I removed mine because one of them cracked.

The O2 sensors are devices that measure the oxygen concentration in your exhaust gas. There are 2 banks on your engine, a left and a right. That means that each side of the engine has it's own tube for exhaust gasses to pass through. There are 2 sensors that are placed in the exhaust system a few feet from the exhaust ports on the engine. These first 2 O2 sensors monitor the performance of the engine, and fine tune it constantly in order to achieve best performance and economy. The other 2 sensors come after the catalytic converters and they monitor catalytic converter efficiency.

I'll let somebody that knows more about the IAC tell you about that.

 

Have 2000 x-Cab f-150, 68,000 miles had it since 14,000. 4x4 4in lift and 33's. Have a programmer, cold air K&N, Flowmaster and a throtte body spacer. Have to run 91 because of the programmer, 10 mpg (205-210) per tank for the past 2+-years. I keep the air and fuel filter clean and changed regularly. No O2 sensor changes yet, and I'm sure those 4 Cataletic converters don't help. Welcome to California!!! If I leave it in over drive, and lug it around the best I have gotten is 11-12. Never better than 13 on the freeway 8-mpg when I pull my 7X9 quad trailer with a whopping 2 quads and fuel. (Even with a tail wind lol). Besides cut a damn hole in the floor board and flinstone it to work I need some serious suggestions. Saw the post about BG44K. What is it and where do I get it. I'm actually considering cutting my nuts off and test driving a New Tacoma tomorrow to cut my gas bill in 1/2. My wife isn't buying the (Babe, I need that next performance part to help with my gas mileage any more! I think she's on to me!!!
Thanks

 

im not much of a mech. but i just cleaned my throttle body, and them 2 port holes on the right side i think, by the "flying saucer" in that area.

anyways i went from 2000 rpms at 30mph to 1500 rpms at 35mph....im sure this will save me alot of gas money down the liine. also threw wd-40 on the iac thing.

 

Ended the last tank at 275, so I picked up 1 mpg, prolly a result of watching my driving style more than anything else. O2 sensors this weekend for me.