O2 sensor location

I am working on a 1998 Z71 with a 350. I retreived codes P0154 and 155(O2 Sensor bank 2 sensor 1) with a scan tool. I measured all four sensor heaters and they checked good. after reinstalling the connectors the check engine light cleared. I am not sure which O2 sensor this is,I was thinking it was on the even cylinder side before the cat, can anyone let me know what is the correct location for this O2 sensor?

Thanks

twross

You are correct.