I had two O2 sensors replaced yesterday and one of them was out again today. What can cause this aside from a faulty sensor?

 

running way to rich and coating them in raw fuel, also if you have a leaky head gasket and have antifreeze getting on them as it blows out of the exhaust port on your head and into the exhaust pipe. Oh leaky oil seal in the turbo causing oil to leak into the exhaust could also cause premature failure. Not saying you have those problems on your car, but I'd be wanting to know why you are going through them. Could be a shorted out wire in the wiring harness, or a burnt through wire. Check the wiring around the engine block and pipes.

 

I agree with Scott.

The most common causes of early sensor failure are deposits on the probe tip that prevent the tip from accurately measuring the amount of oxygen in the exhaust gas.

Sensors can be subjected to extreme temperatures, oil fouling, carbon deposits, and the corrosive effects of a myriad of harmful chemicals during a "normal" life.

Eventually, even the best oxygen sensor, operating in the cleanest engine, will wear out.

But since it was just replaced, I would be willing to bet it's the connector or a faulty wire.

 

Thanks. the shop is going to replace it for no cost so that's good. I'll have them check those two things as well

 

leaded gas.