Hello I just failed my emissions test because of a bad O2 sensor in bank 1 sensor 1. This is the one right in front of the firewall, inside of the exhaust manifold. I was told this is the hardest O2 sensor to get out compared to the rest of them on my car. Well I can see the sensor just dont have any room to get a wrech or socket in their. I bought the new O2 sensor and the O2 socket from advanced auto and just need to know how do I remove this sucker. I been trying to get at it from under the hood. Does anyone know how to remove this O2 sensor, I'd really appreciate the advice.