I have a 97 F-250 HD 4WD 5.8 with an automatic transmission. The truck has 111,000 miles. My problem is when I am driving at any constant speed above 25 mph and I try to accelerate it feels like it is starving for fuel. I can press the accelerator to the floor and it comes to life like there is no problem. I can switch tanks and it has no effect on the problem. This only happens about 25 percent of the time. The only other problem is that after about 15-20 miles of driving the check engine light comes on, it is always code 172 and that is something with the oxygen sensor. In the last 500 miles I have changed the Fuel filter, plugs, wires, rotor button and cap. Any help would be appreciated.

 

did u change the o2 sensor? they are only rated for life of 60k miles...but most last till atleast 100k miles.

 

I would say O2 sensor also, Because the computer ignors the O2 sensor at idle to slight cruise and wide open throttle.

 

When you say it "feels like it is starving for fuel", do you mean it bucks and shudders?

That can be the symptom to a slipping lockup torque-converter. Do a search in the transmission forum for "E4OD" and "lockup", and you'll see that problem described.

 

Thanks for the help, I will change the O2 sensor and see what happens.

 

I changed the O2 sensor last night and haven’t driven the truck yet but I’m sure that will fix the problem. If you have a 250 4WD it is a bear to get to the sensor, first thing to do is take off the skid plate under the transfer case so you can at least see the sensor. I sprayed it with super penetrate and waited 2 hours before trying to remove it. I had the special socket but I could not get it loose with it, I ended up using a short 5” box end wrench and a crow bar to break it loose. It unscrewed by hand once it was loose. That was the easy part, I don’t know what possessed the Ford Engineers to place the connector right on top of the transmission but with all the 4WD “Stuff” in the way you have to be a contortionist to undo the connector. One last thing I took the old one with me to Advance Auto Parts and checked it when he brought out the new one, the computer list two different ones and the difference is the length of the cord. One is a short connector cord and the other is a long, about 14”cord. Mine had to have the long cord, so it pays to take the old parts with you if you can. Thanks again for you help

 

I just did this on my '97.

Only difference is that on a 2wd truck, it's a snap.

I used that special socket, a 1" socket on the end of the tool (the 1/2"-3/8" drive adapter self-destructed pretty dramatically) and a 5' breaker-bar. Of course, most of the threads on the O2 sensor remained in the bung, so I had to use a battery-terminal brush to loosen them up and a small screwdriver to pull out the thread remnants.

 

I drove the truck about 60 miles today and it ran like brand new, no problems with stalling out and the check engine light never came on. Thanks again for the information