02 sensor problem

[bbrewer2005]

02 subaru legacy L

I have replaced my front o2 sensor a couple of times now with no luck.The code keeps coming back every time I replace and clear it. Keep reading for full back story.

 

At 78k miles, the original front o2 sensor went bad. It caused the car to run like complete crap, would lose 90% of power for a few seconds and then come back. Got NO codes. After using google and figuring out it was the o2, i unplugged it and the problems went away, but THEN got the code. So I replaced it with a bosch 17018 sensor (what autozone said fits). All was good for about a year (~7k miles), and then got the same problem as before. Replaced it again, and cleared codes. Well, the code came back again after a few miles, but it was running as if it is unplugged, not like it was when it just went bad. I took the new sensor back again under warranty, and got a new sensor, same problem. It doesnt behave any differently with it plugged in, or unplugged.

 

Has anyone experienced this? Im trying to sell this car, and I dont want this check engine light on, and you can tell it is very slightly down on power, and is drinking the gas. All plugs, and wires, air filter, fuel filter, etc. were replaced when I did the o2 sensor the first time as well. The car has 91k miles on it now.

 

I'm hoping its not something in the harness. There are no exhaust leaks either.