To coobies5,
You have no 'basis' for replacing OX sensors at this time.
.
..Background on these sensors are as follows.
..If there is a real problem with them such as the heater circuits are in trouble, the PCM will detect this and set code.
..If the sensors are contaminated and to slow to respond to oxygen content changes, the PCM will also pick this up as out of limits in background testing the program does and set code.
..The only benifit you might see by replacing them is more precision fuel control. BTW there is a lot of indepth info to know about that, but won't go into it this time.
..This would take very close tracking of fuel use and still be subject to error to even see it for real..
..Bottom line is if you want to spend $100 + on sensors it won't hurt anything.
..You could check your cooling system operating temperature to be sure it's working in the 195 range the program expect it to, and bases timing and fuel on for general system operation.
..As an example; I recently saw my cooling to be operating at 182+/- degrees due to lack of paying attention and not having it programmed into my dash monitor. Don't know how long it's been that way.
..I changed out the thermostat and now have it working at 195 to over 200 depending on the engine loading and road speed.
..The results observed on the monitor is the ignition timing average advance has moved higher and resulted in more throttle response as different from the colder temperatures the motor was running at.
..Hopefully the fuel mileage will increase but have to put some time in to tell that.
..Bottom line is that many try to guess at how to improve a computer controlled system that they really can't do, but can only correct operation that is known to have has fallen out of specs.
..In this case the thermostat looked like brand new as removed after 168,000 miles with no dirt or accumulation in the housing or the intake manifold.
.. It just got fatigued from all the time in use such that it opened too easy and caused the motor average operating temperature to fall at least 10 degrees that the PCM had detected and shifted it operating parameters to accomadate by running the fuel a bit richer ans shifted the timing.
..I can't stress enough how much the computer program is in control.
..It's a very powerfull system in computer jargon..
..Next time I run a trip that I normally take once a month I will be able to see if there is any diference in average running mileage and fuel use from the average seen over the years running the same path repeatedly.
Good luck..

 

dang, yall are replying to me a year later! hahahahaha

@bluegrass - i know what you are talking about, now am a ford certified tech, but at the time i posted that last year, we were just starting our engine operations class. so i was able to learn about how o2 sensors work, switching on and off and how to read pid values and find out if a bank is lean/rich. open loop & closed loop fuel trims


also, about a month before my helicoil failed, i actually picked up 2 motorcraft o2 sensors from rock auto "just in case" and i'll be putting them in when i put my truck back together. i also bought a new thermostat too.

 

In regards to the Thermostat, I gained 3-4 mpgs. On warm days it was hitting 184ish... winter with 0* TEMPS LAST YEAR IT WASN'T EVEN HITTING THE CENTER MARK ON THE GAUGE. Went from 12 back to 16-17 on winter blend

 

I see all the people on the site complaining about bad mpgs cause they aint getting over 15....i would be thrilled with 12 or 13!! the best i ever get out of my 4.6 4x4 is 11.5, If i baby it! An all three of my 97 f150 4.6 4x4's have gotten this same mileage...one completely stock, one 4" lift with 35's, an the one i got now

 

I must say Im fairly happy with my 12 MPG pulling my quads or unloaded, although I wouldnt mind having 14 or 15.
I also like when people point out that we all drive trucks on here,, and fuel mileage is always going to be the *****s..

 

If I wanted good mpgs i woulda kept my 30 mpg kia spectra
I will pick my truck over fuel economy ANY day

 

i don't understand why people say 10 12 mpg is normal they are rated 14 16 mpg

 

The EPA rating are based on a very controlled set of tests. Real world, results are generally lower than the ratings, especially around town.

 

X2

 

What is normal to one owner driver is not to another.
None have the same driving style, speed tendency, lay of the road, weather conditions and temp or use of the truck.
9 to 10 was my mileage towing 12,000 lb gross.
I just came back from a 140 mile tround trip last evening with one passenger.
I got the monitor up to 17 as a 'running average' on the way back which was more down hill than going the other way. If averaging this both ways then the actual average is in the 14.5 to 15.5 range +/-.
One cannot expect great mileage in city/town traffic conditions when the motor is in lower gears and higher RPM often and under accelleration. I drop into the 12 to13 range in town driving.
The other part is tire inflation, passenger loading, A/C load, engine maintaince or fault etc.

 

After skimming through most of this. Guess i wont complain too much about my 97 4x4 reg cab, with 162k on it getting 8-10 mpg with some 33's on it. And yes, thats factoring in the change of tire size. And still the same after a tune up, and new fuel filter. Got a few more things to do yet; I'm hoping it will come up a few mpgs.

 

So hows your 2WD do on MPG?
Nice looking truck.

 

uhhh last trip it was on it pulled 20 +/- on the highway. Which was with 3 people and loaded down. City i havent calculated, but should be around 16-18 easily. Depending if i can leave a foot out of it. I'll have to run a few tanks and see.

 

I just checked mine on my first tank after new plugs and an oil change and i got 12.2, i am goin to test it now again to see what im gettin after i got my dual exhaust and air intake on, but im guessin less than 12 since i like to hear that exhaust!!!! haha

 

I checked my mileage today and I was sad to see it fall down to 13.8 on the last trip, my truck has the ladder rack back on it with a 12ft fiberglass ladder and an additional 500lbs of tools and stuff. Truck weight is right around 5100lbs again, I had to add air bag helpers to keep the rear from compressing and staying that way. I used to be able to drive to other side of the valley and back and make half way back on a tank of gas now its down to one full tank for a round trip. 20 gals for 276 miles. I was around 20mpg a year or so ago with the same vehicle weight.

I did notice the trans slipping in all forward gears, I'm gonna put a shift kit in and see if the sloppy shifting goes away, I have to tow 1100lb trailer with the truck sometimes but its not like I romp on it when towing. If anything I am guilty of driving like an old guy-I drive pretty slow.

I'm gearing up for an X pipe and exhaust change, thinking I might as well get it over with and do the trans, I just haven't done a trans shift kit laying on my back before. Usually do them with me looking down at the tranny.