OXYGEN SENSORS

Can someone tell me where these devils are? I think one is near the manafold.

I was told another one is located near the back. How does a person know what one to replace?

Also , Advance Auto says replacing will show a significant increase in gas mileage uuummmm.. "now I need that"

Does code #141 mean anything?

cobrah

 

code 141 = 02 Sensor Heater Circ., Bank 1 - Sensor2 Malfunction

On my '97 Expedition, there are two 02 sensors under the vehicle, mounted in the exhaust piping. Once you get under there, they will be very obvious.

 

Wavinwayne,

Thanks for the reply, are they close to the motor end or back? Could a ROOKIE change them?

I had a quote of around $75.0 for one...sounds kinda high!


cobrah

 

I can't speak specifically for the Expy, but in general not too much skill is required to change them. If you can find them you can probably change them. All they are is a sensor that is screwed into a nut that is welded in the exhaust pipe. To remove, simply find the sensor, unplug the wires, unscrew. To replace, simply screw it in, and plug in the wires.

I believe in the Expy's there is one located before the CAT and one after it. Just follow the exhaust until you find a sensor with wires coming out of it stuck in the side of the exhaust.


$75 sounds a little on the high side, but not rediculously so. The O2 sensor for my Wrangler (last one I changed) ran between $42 and $60. I just checked NAPA and they list Bosch OEM replacements for $49.

 

Pitrow...

Much thanks , I followed the exhaust from the manafold and found the sensors.

One sensor is on one side, the other is on the opposite exhaust, not sure though where the wires disconnect. It looks like the wires go over the trans. to the other side. I had to lay on my back on the ground and couldn't move around to trace.

You have been a big help...think I'll try to replace them myself, don't look to
complex. (If I find where the wires connect!!! )

97 4X4 EB 5.4L cobrah

 

Not real sure which O2 sensors you are trying to change, but if you are changing the ones that measure engine efficiency (those closest to the engine) then you can access those through the fender wells. The O2's after the cats just measure cat efficiency and are for emissions purposes only.

 

This is the reading ...code 141 = 02 Sensor Heater Circ., Bank 1 - Sensor2 Malfunction.

Where are these located?

cobrah

 

I am not real sure but I believe that to be a sensor after the cats. Call your local Ford dealer and ask them, tell them you need to know which O2 sensor to buy from them. Also from what I hear you will want to stay with Motorcraft sensors, as others say Bosch fail prematurely.

 

There are 4 of them on my 200o expedition, one in in each exhaust manifold and one behind each catylic converter. I just replaced the back two over the weekend and it wasn't too bad. They were located right behind the catylic converters and I had to loosen the exhaust shields to get to them and overall it was a simple replacement. I purchased replacement made by Bosch from Autozone for 49.95 each. Made a lot of difference on acceleration and idling and it seems to have helped the gas mileage.

 

I understand these sensors should be replaced every 100,000 mi. at the latest time. And I was also told that if a 5.4 is only getting 10.0 mpg these sensors should be replaced. As they play an importance to fuel consumption.

How do these sensors disconnect from the electrical wire? I have only looked at them from on my back under the veh. is it a kinda "plug in" or do ya have to trace wires down?

Much appreciation! cobrah

 

They are all plug and play. Just feel the wires coming out of the sensor back till you reach the connectors, just unplug and replace.

The rear O2 sensors have nothing to do with fuel economy, nor make the truck run better. These O2's only measure the quality of the exhaust gases coming out of the converters for emission purposes only. The FRONT O2 sensors will affect your MPG, and how the vehicles runs overall, as these measure the exhaust coming out of the engine and compensate when needed.

 

Thats good to know if one is getting poor milage as I do... wonder if you could soak these suckers in a solvent and reuse?

For all four... it's a price tag..

cpbrah

 

there are some oxygen sensor "safe" solvents out there that you can use. Try it and see if it works. worst case your out $5 for the can of solvent, best is you save $80 + for another year or so.

 

You know what...I think I'm gonna try it. Probabnly this week-end if it don't rain.

cobrah

 

Sorry for the late reply. I replaced both of mine on a '97 Expy, thanks to my son's small hands. The one underneath the drivers side was easy, the other one needed small hands. I also borrowed the sensor socket from the Advance Auto Parts store in town. It is just a socket with a slit to allow for the wires.