So after experiencing a significant mileage drop in my '00 5.4l F150, from 15 mpg to 11mpg, I figured it was time to change the O2 sensors, clean the throttle body and IAC, MAF, etc... I bought the truck w/ 77k miles, and I'm at about 104k now. From what I can tell, the guy who owned it did most required maintenance, but I don't think he garaged it, because of the significant amount of rust on underbody. Living in northern VT on a dirt road, the rust has only gotten worse since I've owned it, and my garage won't fit it (it has the 8 ft bed), so its stays outside all winter long. Anyway, I read all the posts regarding the O2 sensors, and prepared everything I needed.. Those suckers are SEIZED in pretty damn good! The cranked down on the passenger side sensor with everything I had (and I was turning the right way, righty loosey in this case) pretty much bending the tools and getting not a peep out of the sensor. I also managed to dislodge the female end of the wire (didn't take much, unfortuantley) so it will probably flop around for the rest of its life. After an hour or so of that, I moved onto the drivers side.. this one was much easier to get to.. got the O2 tool on the sensor, and nothing.. not a move.. I little harder and finally it moved.. oh wait, that wasn't the sensor, that was the sensor nut stripping out! It was so rusted the nut around the sensor is now pretty much round, AND i managed to crimp the sensor a little in the process.. Fortuneatly I hooked them both back in, and the truck works fine. So the question is now what the heck to do! A mechanic friend who lives in the area stopped by to check it out, did his best to dislodge the passenger side, and confirmed that it was seized in.. He suggested heating with a torch, which I didn't want to do on my own (he was hesitant to get too involved).. But the driver side I wonder if even heating will do anything, since the nut is stripped. Whats the worst case scenario with this, assuming I really want them changed?? New exhaust?? What would that entail?

On to the second project, taking out the throttle body and cleaning it.. This project was a little daunting at first, but really was straight forward once i got into it. I got the throttle body of and was a little shocked..the thing was like perfectly clean. First I noticed the lower intake, which in every picture I see on other peoples trucks, seems pretty corroded. Mine had a jet black coating on it that looked like glossy laquer. Wiping my finger on it revealed that it was super smooth and just had a little bit of oily residue on it. THe throttle body itself was just shiny silver, and looked pretty much like the after pictures people post after the cleaning.. Same with the IAC, a tiny amount of residue but really nothing to even try and clean off. A little disheartened, I put it all back together. I'm read in some posts that some engines have a coating, and shouldn't be cleaned.. I guess this is one of those engines? Seemed like most people disagreed with that though.

So, 2 parts of my afternoon project turned out pretty crappy.. Fortunately I also got the fuel filter changed, replaced all the ignition coils, and put in all new fuel injectors (not exactly new, ordered them from the guy on Ebay who ultrasonically cleans used injectors and sells them. While they were visibly not "new" injectors, they looked really good, and looked a hell of a lot better then the ones I took out of my engine..) After all that, taking it for a little test drive, I immediatley noticed increased throttle response, and harder, smoother acceleration up some steep hills in my area.. The test will really come when I have to tow my tractor (about 6k with trailer).

Really, any suggestions on what to do with the O2 sensors would be helpful..

 

Yea , you want to heat them real good / get the O2 bung just about glowing before you kill the torch - Make sure the harness is not any where near.

I hope you have the right tool -



Or it's not going to work.

You have to heat hot enough to break that bond that has formed inside or you'll rip the threads right out of the O2 bung, then your screwed - {{{been there done that}}} The heat will expand the bung threads and hopefully sever the whats bonding the two together, thus break it free without damage to the important part. What ever you do - don't damage any wires or that plug , it's easy to damage the wires , just be real careful there, there sensitive when in operation.

Replace with BOSCH units - OEM only. I tried other and went down to 9mpg / swapped w OEM and I went up to 17mpg.

 

I've had it happen. Sometimes after striping (with that cheap tool) them you have to get a socket on them. The way I've done that is cut the end of the sensor off with an angle grinder then 7/8 socket with a breaker bar, Those cheap tools will flex but a socket wont. Heating it up with a propane torch might help. If you dont have the stuff to do it haul it over to the nearest muffler shop and let them do it.

 

Holy F -

 

Thanks for the replies -- yup, definitely have the sensor tool.. its just stuck on there. I don't feel comfortable using a torch in such close quarters (shimmied in between the wheel and frame, or under the truck, so I think i'm just going to bring it to a shop that has a lift and hope for the best.

So regarding the Bosch sensors... your saying the "standard OE performance plus" sensors I got from Bond auto parts may actually lower my mileage??!! I think autozone has bosch, so I guess I better return these to bond.

When I was out driving today, the "service engine soon" light came on.. Guess it could be anything, but hoping its the O2 sensor that I bent. I'll have to stop by and get the code read. Nothing like a project that leads to more projects!

 

great way. I never thought about grinding that mo fo off

 

Yea, have a shop do it . Those O2 bungs are thick and take allot of heat sometimes . If the bung gets damaged , you could be looking at big labor charge to fix, you definitely need the heat and it's a good thing they didn't come loose at this point - given the probable outcome of that. Even the slightest damage may cause the bung to leak which causes more problems for you in the future.

If the sensor is bent or wires have been chaffed at the top of the sensor(that's what usually happens) -the sensor can read incorrectly and set code(probably where your at right now) - Like I said those wires are sensitive.

I tried Borg/Warner sensors. I had the correct part # for my year - The computer cross referenced my OEM Bosch Sensors with the B/W replacements.

The engine seemed to run fine, I couldn't tell any difference. The difference was at the pump. That still blows my mind, that truck has always been real good on fuel unless I was pulling 7000 lbs, then it ate it up. The only change I made at the time was new forward O2 sensors. A tech had suggested running my old units to see if I noticed a difference in mileage. Sure enough , my economy returned. I then purchased new OEM Bosch Sensors and everything is normal - I average 15-17 mpg and higher on long trips. I've got 20 mpg from MI to PA at one time.

Yea , I would stick with the OEM sensors there.

 

If you go to midas or mineke they have the bosch sensors. They (mineke) Quoted me 170 bucks to do it part included per sensor. I did it myself. On these trucks an angle grinder might not fit. Might have to saw it off. Hack saw or maybe a rip saw would fit.

 

I never had a problem with the forward sensor's - But after 200,000 miles - I tried to change the rears

I had to use allot of heat and "jethat method" (slice & dice) to remove those damn things.

 

definitely need that special socket. i learned the hard way and tryed using a cheap open end wrench and rounded it off. i got lucky and was able to get a small pipe wrench in there and get them out.

 

Well, headed back to Bond today to return the O2 sensors.. got back $170 after tax. Went over to autozone and bought the bosche sensors -- total was $95 after tax!!! (included 10% discount for buying 2 sensors).. I was happily shocked. Is bond just a ripoff? How can those OE sensors be almost double the price?

Also had the guy at autozone read my "service engine soon" light.. but he couldn't get a read on it. I was annoyed about this, he said maybe I just blew a fuse. Doubt that. What's the diff. between a service engine soon light and check engine light?? I can imagine the check engine light is more serious. I had an old honda that threw a light every 3500 miles to remind of oil change, but i'm not that optimistic that this is the case.

 

Yea , CEL (Lamp) runs thru your cigarette lighter fuse and PP (Aux.PowerPort)

CEL = Check Engine Light

SES= Service Engine Soon

MIL= Malfunction Indicator Lamp

All the same

Yea , you got a good price on those O2'S - http://www.autopartswarehouse.com/se...6999+1616+9167

 

NGK also makes an O2 for our trucks. Trust me I know. Anyway, NGK is the largest OEM supplier of O2's.
Just a tidbit of info for ya.

 

Theres quite a few suppliers, but how do you know they meet or exceed Ford spec? You don't , so it's a chance you take with those. I tried others and found that the OEM Bosch where the best choice.

Stick with OEM on those sensors or you could be pulling your hair out in the future - been there done that.

 

I have had really good luck with PB Blaster. Just let it sit on there for a day keep it well soaked you will be amazed I had a pulley on a lawnmower thought I would never get off 3 jaw puller and blaster and right off. Good Luck. Also use never- seize on threads when putting back together.