So I attempted to replace my upstream O2 sensor and everything went smooth other than the fact that when I went to put the new one in, I realized that I had been sold the downstream...so I put the old one back in.
Now my engine has a terrible vibration. It was running very smooth until this point. Could something wrong with the O2 sensor cause this?
It seems to drive fine, the vibration feels to be just at idle, both in park and drive.
I could really use some suggestions.
Thanks!