98 Taurus DOHC V6 3.0 Front Bank O2 Sensor problem

I have recently replaced my front bank O2 Sensor approx. three months ago only to have it be diagnosed once again, as being faulty. It was a Bosch brand (Non-OEM; obviously trying to save that $40 difference) and now having to take it to the Ford Dealership nearby; just to learn that it is faulty. Are there any known repetitive problems with these, or was it just that one particular instance of me purchasing a 'lemon' part? :banghead:

its not always an o2 sensor. these get clogged up by carbon deposits, they do break easy, usually when taking them out if your not careful, but you have other problems in your exhuast system other than this. my 99 has had the engine light on for almost 2 yrs. for this with no decreased engine capacity....when the tax money comes in im gonna start cleanning all this out parts at a time ( egr valve assembly is were most of it is).

but most of your garages like making the mark up on o2 sensors, just beware. its easy to change and get the customer out of the shop

DVK

I have a 1998 Ford Taurus that is doing the exact same thing. The "Service Engine Soon" light came on and the computer detected HO2S Bank 1, Sensor 1, so it was replaced with a BOSCH. Then the light came back on with HO2S Bank 2, Sensor 1, so it was replaced with a BOSCH. Now, its back on with HO2S Bank 1, Sensor 1 and HO2S Bank 2, Sensor 2. The code which is being displayed is PO135 & PO155, which technically is the exact same code just PO155 is downstream and PO135 is upstream. I have a ALLDATA print out that shows possible causes for false readings. They are:
* Blown fuse * Short to VPWR in harness or HO2S
* Water in harness connector *Open VPWR or GND circuit
* Low Battery voltage * HO2S heater *PCM (computer)
* Poor electrical connections from PCM to HO2S sensor

I hope that this can help you because mine is going to go to the shop due to I am NOT mechanically inclined especially where the electrical is involved.

If you should have any additional finding on yours I would appreciate it if you would share.

Have a great day.
TM :chair:

Just called a reputable Ford dealership in my area. They suggested getting a can of Carb and Choke cleaner and cleaning the throttle body. The tech said that if the sensors have been replaced that more than likely it would be carbon build up that would cause the car to run leaner which would cause the HO2S Sensors to show a false reading. He said that sometimes you can get it clean enough on your own, otherwise it may require a professional cleaning which would involve dismantlement. I'm going to give the carb & choke cleaner at home a try and will let you all know what happens.

Keep your fingers crossed and say a prayer.

TM :dunno:

Well, back to square one. It was filthy but the light still came back on right away. Oh well, at least I tried.

TM :dunno:[/QUOTE]