Oxygen sensor location for replacement?

Here is a guide to help locate and change out the sensors, the diagrams below show the location for your car.

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

Check out the diagrams (Below). Please let us know what you find.

My ford is having problems idling and staying started. It coded problems with 2 of the o2 sensors and mass air sensors. How much will this cost to take to a dealer ship. estimate

Depends on what there hourly rate is and what you are going to need replaced? Just because you have oxygen sensor codes or mass meter codes does not mean that you have a problem with those items. I suspect that you have a vacuum leak and that is why your truck keeps stalling out. And because you have a vacuum leak the oxygen sensors are reporting what they see and the mass air flow is reporing what it sees and now there is some conflict with the mass air flow sensor and the oxygen sensor so the light triggers. On the passenger side there is the pcv valve. trace the vacuum hose. It goes to the back of the intake. Behinde it the vacuum hose collapses and breaks causing a massive leak and your truck to stall. It is pretty hard to reach back there because it is tight. Let me know what you find.

Thanks that vacuum hose was dry rotted and I replaced it. thanks for the help

Electrical problem
1999 Ford Expedition V8 Four Wheel Drive Automatic 98354. miles

I took my ex to advance auto used their code reader to find out engine lite is telling me o2 sensor malfuction he said there are four 2 befor 2 aft the cat, where is the sensor located on the pipe top bottom sides. thanks

I have to double check, but I don't think they have 4. Which V8 do you have? As far as location, they are usually mounted to the side of the exhaust.

Engine Performance problem
1998 Ford Expedition Four Wheel Drive Automatic 140000 miles

Would having a bad O2 sensor cause my vehicle to idle really rough and have trouble starting up unless I give it gas intermittently?

I would check and clean the Idle Air Control Valve first. Remove it, spray and soak it with brake cleaner. It is on top of the throttle body; should be easily accessed. If the sputtering at idle continues, replace the IAC valve.

Bad O2 sensors wouldn't necessarily make the engine run rough because they simply provide feedback to the PCM (car computer) as to current operating parameters. In fact, you can disconnect them and the engine will appear to run almost the same.

Engine Mechanical problem
1998 Ford Expedition V8 Two Wheel Drive Automatic

hi I need to know if is any way to test the 02 sensors and the EGR valve ? thanks for you help

Hello Information on testing your oxygen sensor(s) can be found on our Service Repairs page. Just follow the link below. https://www.2carpros.com/how_to/how_to_test_oxygen_sensor.htm To test the EGR valve operation, start the engine and then disconnect the control hose (light blue dot in 2.). The EGR valve should open and engine should slow or hesitate. If disconnecting the hose makes no difference, either the hose is leaky/ blocked or the EGR exhaust gas pipes are blocked.

Thanks for using 2CarPros.com!

can,t remove the sensor on the front passenger side we heated it and still can,t get it out any suggestions

go in through the right side tire well. we use a special o2 sensor rachett handle to break it loose. it is very tight.

Roy

Its a 7\8th wrench or socket

i tried that still would not come out i even applied heat and still no luck i even took out transmission dip stick to get to it

Did you heat the pipe ? Not the 02 sensor. @ this point you might need a new pipe or have to repair the 02 hole when it comes out. Is the nut striping or just not braking free?

i do have the rethreader tool cause one of the other ones had to be re treaded and i heated the pipe and the nut just ain,t braking free the nut is not striped yet but i,m afaid that might happen the worst part i seen the nut move alittle bit now it won,t move any further

Work it back and forth spraying it with lube.

Where is the heated upflow 02 sesor located on this vehicle?

The upstream heated O2 sensor is on the exhaust before the converter close to the engine. Here is a picture. It is the best I could find. I hope it helps.

Let me know if you have other questions. Joe