My check engine light had be coming off and on for about a month most of the time it was on but sometimes it would randomly turn off. So about 3 weeks ago I went down to autozone had them pull the codes and it is o2 sensor bank 2 sensor 2. So I went out bought a new o2 sensor and put the o2 sensor in the back bank on the drivers side. Everything was fine until yesterday when it came back on again. Went to autozone today has them pull the codes same exact thing o2 sensor bank 2 sensor 2. Is bank 2 sensor 2 the back bank and drivers side? I also have a MAC O/R H-pipe with MIL's. I'm not sure what is wrong I put the new o2 on and it was fine for about 3 weeks now the check engine light came back on with the same codes. Anybody know what could be wrong?