O2 Sensor out for the 2nd time.

When I bought my car about 2 months ago, the O2 sensor was bad. I took it out and the thing looked like it had been in a fire. I replace it with an $85 one i bought from autozone. It worked great. But about a week later it was out agian and my gas milage is terrible. One friend mentioned to me that the crappy loud exhaust might be causing the O2 sensor to keep going out. Anyone know if thats the problem? And if not, what the problem is? Oh yeah, i guess there are two sensors. I'm pretty sure it was the Lower sensor because I had to get underneath my car to replace it. i dont know the technical term for which one it is.

When I bought my car about 2 months ago, the O2 sensor was bad. I took it out and the thing looked like it had been in a fire. I replace it with an $85 one i bought from autozone. It worked great. But about a week later it was out agian and my gas milage is terrible. One friend mentioned to me that the crappy loud exhaust might be causing the O2 sensor to keep going out. Anyone know if thats the problem? And if not, what the problem is? Oh yeah, i guess there are two sensors. I'm pretty sure it was the Lower sensor because I had to get underneath my car to replace it. i dont know the technical term for which one it is.

You have them before the cat and after. There are o2's and ho2's the later is a electrically heated for a quicker accurate signal. Thus it has more wires probably three or four. The o2 after the cat basically is checking on the one before the cat. Are you getting codes? Did you use antiseize? There is a special antiseize for O2's you might of contaminated it. How does the new one look after a week? If it is bad /melted check your voltages and grounds. However you might have gotten a bad one that worked for a while.

And as for the loud exhaust probably not, but exhaust leaks before the 02's yes

I'll check back on fri...

i dont trust autozone parts...anti-seize isn't a must...but theres no such thing as "special anti-seize" they just call it that and put a higher price on it so people buy it...but if ur not familar w/ using it dont worry...most o2's u get come w/ it on already...all ur o2's are H02's...and u do have 2...i would check to see if your cat. is working before doing anything else though...