I'm having a problem with mine on bank 2 and was told today by mechanic that #1 should fluctuate between lean and rich and #2 should fluctuate within 1volt which is what he said mine were doing. Then he suggest we start solving the problem by first changing all 4 o2 sensor and if that dont work then converters. I'm not sure why I'd need to replace the o2 sensors if they are reading like he says they are supposed to?

 

I wouldn't think so either to be honest but then again I'm no mechanic either...I just know that all of mine are reading equal and it feels like my truck is holding back a lot of power

 

check your coils and plugs i had the same issue on my Z71 and i had gutted cats on it so it has nothing to do with the cat being gutted if there not gutted the may be getting pluged up hope this helps