Replaced one of the sensors about a month ago.Today check engine light came on and I went to auto zone to see what was up.They told me 2 o2 sensor were bad.The one I replaced and another on the other side.What causes them to fail like that?

 

What code did you get exactly?

 

Not sure of the code.
He said the sensors were slow to respond

 

Blood - do you have extensions for Long Tube Headers installed?

 

I have longtubes and I'm fighting the same thing. No answers yet, and I'm not convinced I'm getting enough help or interest from my tuner (Bamachips).

Read this thread, especially the end of page 3 http://www.moddedmustangs.com/forums...ning-rich.html

 

I have OBX long tube headers installed not sure of the extensions.Everything was done b4 I bought the car.

 

you need a tweak in the tune to compensate for the delayed response. This is due to the sensors being farther downstream from the stock location.

 

thanks

 

Tune needs to be set to disable, its supposed to throw a light as you have changed your carbon footprint, your illegal, just have tuner remove the DTC trigger !!! lol

 

Did you replace the O2 sensor with a Motorcraft or Ford sensor? If you used an Auto Zone no-name brand, which was probably half the price, be advised that they suck.