It is very rare.
I have a 2004 V6 with 150000km and despite the abuse I've given to the poor thing the O2s work good and sound.

 

O2 sensors have come a LONG way from just 10-15 years ago. These days, they manage to last the life of the vehicle with that usually being around 150k miles on average. It was just over 15 years ago when O2 sensors usually lasted about 90k miles, and started becoming inefficient at around 60k miles.

If your O2 sensors are running out of spec, but not enough to trigger a check engine light, it is possible that you could pick up a small gain in fuel economy. Of course it just depends on whether you want to spend that kind of time as changing out O2 sensors can really be a bitch.

 

My O2 sensor failed. Had to replace it. Made a huge difference in gas mileage as well. Truck is a 01 Tribute 3.0L.

 

Tousley and Roseville Midway are good parts dealerships. Roseville Midway is much closer for me though

 

i currently have an O2 sensor that has been bad for about 6 months. its on the passenger side rear of the truck. i need to get around to fixing it...

2001 V6 XLT 119,000m

 

i currently have an O2 sensor that has been bad for about 6 months. its on the passenger side rear of the truck. i need to get around to fixing it...

2001 V6 XLT 119,000m

How do you know it's bad?

 

i currently have an O2 sensor that has been bad for about 6 months. its on the passenger side rear of the truck. i need to get around to fixing it...

2001 V6 XLT 119,000m

How do you know it's bad?

check engine light is on. and my mechanic has plugged in his computer numerous times and its always the same thing

 

Does anyone have a diagram of the all the sensors with the name like bank 1 or bank 2? I am about to replace mine. My bank 1 sensor 2 and Bank 2 sensor 1 are bad. I don't know which one is which on motor. By the way it 2003 v6 escape.

 

On the V6 engine, Bank 1 is the exhaust manifold closest to the firewall. Bank 2 is the exhaust manifold closest to the radiator. Sensor 1 is the sensor closest to the engine on the exhaust manifold. Sensor 2 is further downstream on the manifold. The good news is that Bank 1, Sensor 2 is easy to replace. Take you 5 minutes if that. The bad news is that Bank 2, Sensor 1 is a major PITA ... at least on my vehicle. I finally took it to a mechanic to get it replaced. The other two sensors are also pretty easy.

 

O2's going bad in the days of non heated were very common and also still in Dodge products because they run so pig rich. But not so much on Ford or Chevy products.

That's not to say they don't go bad but that is more due to an other problem like burning oil or poor or weak ignition.

 

Never had one go, but had one that was lazy as they call it. It ended up being the wiring for the heater circuit of 02 sesnor that was corroded so bad it wouldn't heat it up fast enough so i just had it replaced.

.So check the wiring connections to the 02 sesnor.

 

Thanks for the info. Well I did replace those sensors. Yes Bank 1 sensor was easy as pie. Bank 2 sensor 1 was a PITA!. I was able to get it. The hardest part was getting a wrench on it to tighten or loosen. I was thinking the same thing about taking it to a mechanic but I really didn't want to. So I stepped back and thought for a minute then I jumped back in and got it. Now time will only tell if it worked. I was getting like 12-15 miles per gallon. I used to get 21-25 so hopefully it fixes it. Once again thank you for the help of info!

 

On the V6 engine, Bank 1 is the exhaust manifold closest to the firewall. Bank 2 is the exhaust manifold closest to the radiator. Sensor 1 is the sensor closest to the engine on the exhaust manifold. Sensor 2 is further downstream on the manifold. The good news is that Bank 1, Sensor 2 is easy to replace. Take you 5 minutes if that. The bad news is that Bank 2, Sensor 1 is a major PITA ... at least on my vehicle. I finally took it to a mechanic to get it replaced. The other two sensors are also pretty easy.

Downstream sensors (sensor 2) seldom fail. That sensor is know as the cat monitor. If the oxygen readings a out of spec, it is an indication that the cat is not efficient.

Let me explain. A properly functioning upstream oxygen sensor is constantly switching, reading from rich to lean rapidly, as the exhaust pulses from the exhaust valves pass through. The downstream sensor, reading oxygen after the cat, is buffered by the cat, so it switches very slow if at all. The cat monitor in the PCM recognizes a problem if the downstream switching rate too closely matches the upstream switching rate. The cat monitor does not run constantly. It only runs when certain other monitors have run and other conditions have been met, such as a certain drive length time and returning to idle.

Besides a lazy cat, this can also be from a lazy upstream sensor, so sometimes a cat efficiency code can be cured with a fresh upstream sensor.

Before ending, I should mention that a downstream sensor can be bad because its heater circuit is messed up, but that is a different code from the cat efficiency code.

One last thing, the bank 1 (rear) upstream sensor is very difficult to access. There is an oxygen sensor tool that sort of looks like a partial socket crowfoot that is attached to its handle with a flex joint that makes access much easier and is worth every penny. With that tool, access is from the bottom. Attempting to access the sensor with a conventional oxygen sensor socket is usually from above. Some have had success with a short combination wrench from below, but it is a fight. The other three are reasonably easy.