Mini420

I have a 1997 E420 and the check engine light came on. I resetted it three days ago, and the light came back on today. The OBD2 program says 2nd sensor bank 1 failure, which sensor is that? I checked on past threads and seems like www.oxygensensors.com was helpful. But when I clicked on the site, it has been closed. Any other site that would have instructions on how to replace the oxygen sensor? Thank you.

230KBenz

Bank one is on the right side, all you need is a 22 mm wrench to take it out. The new one will come with anti siese on it already.