Bad oxygen sensors?

Tiny
TCSTAPES
  • MEMBER
  • 1996 FORD F-150
  • V8
  • 4WD
  • AUTOMATIC
  • 120,000 MILES
I am showing a 0401 and 1131 on my scangauge. I guess I may have a ad O2 sensor? Would this affect my fuel mileage a lot? I am only getting about 13 mpg on the highway.
Thanks,
Todd
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Monday, December 28th, 2009 AT 9:26 PM

51 Replies

Tiny
BLUELIGHTNIN6
  • EXPERT
Yes faulty oxygen sensors will definitely hurt your MPG. faulty oxygen sensors can also lead to destroying the catalytic converter here is a guide to help change them with instructions below to show you how on your car.

https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

Check out the diagrams (Below). Please let us know what happens.
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Monday, December 28th, 2009 AT 9:33 PM
Tiny
ELIMILLSAP
  • MEMBER
  • 1996 FORD F-150
  • 6 CYL
  • 2WD
  • MANUAL
  • 113,000 MILES
I have a 1996 f-150 4.9 I6 with 113000 miles. It has two o2 sensors up stream. 1 on the headers of the first 3 cyclinders and 1 on the header of the last 3 cyclinders. I got the first sensor replaced and tried to replace the second but in doing so stripped the bolt. I am not planning on keeping the truck very much longer. Can I hard wire the second sensor into the first and make the light go off? Ie pass emmisons test? This is all assuming that it is second sensor in there now is shot and engine is fine.
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
MASTERTECHTIM
  • EXPERT
First of all why are you replacing them? Any codes?
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
ELIMILLSAP
  • MEMBER
Yeah the code said the upstream oxygen sensor failed.I forget which bank but I know it was up stream. I have been driving on it for about 10,000 miles.I know bad thing. I have to get it fixed before I can get another sticker. If I have to sink to much money to get it fixed I am going to face the inevitable and get a new vehichle.
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
MASTERTECHTIM
  • EXPERT
Well you already have the o2 sensor right. Id bring it to a local independant repair shop. I dont care how stripped it is I can replace any o2 sensor in an hour. We(independant repair shops) deal with broken stripped stuff all the time. Youd be surprised how fast it can be fixed by a mechanic thats done it a hundred times already. Give it a shot. Tell them up front you dont want to pay more than an hour labor. Your garage should do it. If they dont go to the next one, someone will want your business, trust me. Let us know how you make out.
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
ELIMILLSAP
  • MEMBER
Thanks for the advice! I'll let you know how it turns out.
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
ELIMILLSAP
  • MEMBER
Welll I got it into the mechanic. It ended up taking 2 hours to replace but I can live with that. They ended up havin to heat it up first. But in doing so screwed up the threads on the header. Then they retaped the hole. The good news the truck seems to be runing better than it ever has! Anyways thanks for the advice.

-Eli
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
GIBBRPM
  • MEMBER
  • 1996 FORD F-150
  • 6 CYL
  • 4WD
  • AUTOMATIC
I am working on a 1996 F-150 4x4, 4.9 auto, it keeps throwing too lean codes for bank 1 and bank 2 but I have changed the O2 sensors. That didn't help, any ideas? Also occassionally it won't start after it has been driven but if you let it sit for a while it starts fine.
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
DOCFIXIT
  • EXPERT
Codes P0171 and P0174? Fuel pressure checked? Checked for vacuum leaks? Exhaust leaks?
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
RASMATAZ
  • EXPERT
Lean fuel condition could be caused by one of the following below:

1. Vacuum leaks
2. EGR and PCV valve.
3. Low fuel pressure.
4. Dirty fuel injectors.
5. Mass Air Flow Sensor.
6. Oxygen Sensor.
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
JON WOOD
  • MEMBER
  • 1996 FORD F-150
  • V8
  • 2WD
  • AUTOMATIC
  • 169,000 MILES
Hi guys, I installed new exhast on my 96 f-150 2 in 2out with a flowmaster super 40. Every thing is stock with a fresh tuneup (Motorcraft parts).I did not touch the two front 02 sensors and welded the 02 sensor that was in the cat in the new pipe. My gas mileage now is bad. Talking to some friends they say that the cat 02 gets real hot and thats not happening now. Do I replace the cat 02 with something new or fool the computer somehow? Thanks, jon
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
MERLIN2021
  • EXPERT
Check engine light on? When you say you welded the O2, do you mean you actually welded the O2 itself, or the new thread hole? If you welded an O2, you may have destroyed it. Welding heat is higher than the operating range of the sensor, and it probably burned the O2 heating element. I would replace ALL O2 sensors with the mileage on your truck. Also if the original position of the sensor was in the cat, put it back there. It's designed to sense oxygen at that point!
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
JON WOOD
  • MEMBER
I removed the 02 sensor from the threaded base before welding. All of the 02's have been replaced with new parts. The cats are not in the exhast system now. The the cat 02 is now reading temp in the pipe. Can I change that 02 with a different one with a different heat range? I understand the cat 02 is not getting as hot as it was when it was in the cat. Is there way to take that 02 sensor out of the program with the computer? My gas mileage is bad, and she smells like she running rich. Thanks for your help. Jon Check engine light is not on.
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
MERLIN2021
  • EXPERT
Your check engine light should be on and P0420 code should be set. There is NO PCM reflash for converter removal that I know of. Your ONLY solution is to put a good cat back on it.
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
CJ MEDEVAC
  • EXPERT
Merlin2021,

Member me?

See my profile

I did a lot of experimenting with O2s, when I installed one in my exhaust, just where the Hedder dumps in.

I did quite a bit of checking when I was doing this (You were my very 1st answerer here at this site) Isn't that special!!!!........My question was about using a O2 sensor to Select the correct JETS, my 4 Barrel Holley Carburetor........almost 2 years ago.

I used both a DIGITAL Voltmeter, set on Millivolts, and also the AIR/ FUEL METER, it uses LED lights RED (lean) Yellow (stoich [close 14.7:1 perfect burn] ) and Green (rich)

Both methods are good for me, voltmeter is more accurate, but hard to keep up with........The lights really show whats going on with the O2 sensor if you are driving alone.

This method sorta sounds stupid for a Carburated CJ 5 JEEP........But after I finally figured out the factor that was throwing me off with JET CHANGING (wrong PCV for the way my engine was configured) , The Darn Jetting got EZ and I was able to Tune my Carb, to make it as efficient as it could be, with the way I drive.

Now, When things were screwy, I put different ones into a COMPUTER CONTROLLED CAR, just to see what both my Voltmeter and the A/F gauge would do. You simply just Jumper wire into the sender connection, lets the computer still use the info, and you can read it too.

Just like they said, The Computer keeps the Vmeter at about 450 MV and the Add On A/F Meter in the middle of the yellow light band (as it constantly adjusts for too rich and too lean) Does this really fast!...........Carb cannot keep up or rather hold this Efficient burn!....But it will help you get the carb right, a lot EZer than "PLUG CUTS", or keeping up with MPG all the time.

Moral of my NOVEL

If you hook up a Air/Fuel Meter or Voltmeter to the EXISTING O2......see what its doing...........Then swap to a new oneNot designed for the CAT! (they come heated and unheated) Try to find an inexpensive one that Connects in the same to your wires, and try it, see if starts showing about 450MV or yellow lights

A small Ma and Pop self service auto salvage yard might yield some really cheap TEST DUMMIES---Insure you write down vehicle info for each (yr, engine, make) so that if you find a winner----you can get a new one for THAT particular application.

I know the other sensors and O2s come into play with all of this, but what should the MV Output be on the CAT O2 if it were straight out of the FORD assembly line?

OK, I shut up now, I am an IDIOT, I am a Plumber with Jeeps.........Scold me now, Merlin2021

The Medic

My Air/Fuel Meter is on my column, beside the tach.


https://www.2carpros.com/forum/automotive_pictures/411289_straight_in_right_lane12_oclock_1.jpg

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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
MERLIN2021
  • EXPERT
Your old Jeep dosent have the same type PCM as a 96 Ford, any model. It constantly tries to achieve a 14.7-1 air fuel ratio, controlled by the PCM. An unheated O2 will not perform in these vehicles. Soon ALL states that get federal money for highway projects will require the vehicle to have the same exhaust configuration the car was built with. NO acceptions. Also NO carb on this truck Fuel injected, and his PCM cannot get the A?F right, because the sensor data is wrong. It is trying to enrich the fuel to cause the cat to heat up, his PCM is stuck in warm up mode. (RICH). CJMEDEVAC, I don't mind help if I ask for it, but I don't like Monkey wrenches thrown in my direction. If your advice is followed, will you buy the new PCM for this Ford?
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
MIAIMIOVERTON
  • MEMBER
  • 1995 FORD F-150
  • 6 CYL
  • 2WD
  • MANUAL
  • 243,820 MILES
What could happen if I took my O2 sensor off my exhaust system?
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
BLACKOP555
  • EXPERT
Well first of all your truck will hardly run properly if you manage to get it started. Next you will have too lean of fuel resulting in a lack of power and acceleration, or you will have too rich of a fuel mixture causing excessive gas burning. Either one will wear out your engine over time.
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Thursday, September 10th, 2020 AT 6:43 PM (Merged)
Tiny
SAMUELL
  • MEMBER
  • 1994 FORD F-150
  • 4.9L
  • 6 CYL
  • 4WD
  • MANUAL
  • 135,000 MILES
I cannot exceed 63 mph in fifth gear (overdrive). I need to put an exhaust system on, and my o2 sensor is not hooked up. Could this be the reason? Thanks for any answers.
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Thursday, September 10th, 2020 AT 6:44 PM (Merged)
Tiny
WRENCHTECH
  • EXPERT
If you have an exhaust restriction, that could definitely be your issue.
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Thursday, September 10th, 2020 AT 6:44 PM (Merged)

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