o2 help

[LS1_Sickness]

i have an aeroforce tech gauge. o2 1 is working good its jumping around o2 2 is pretty much steady at 440 mv and o2 3 is jumping around. there is no o2 4 for me to choose for the gauge to read. i know i have 4 o2's. so what i did is unplug one see what the gauge reads when i did driver upstream it made o2 1 steady at 440. then i did driverside down stream that made no diff on the read outs. so i figured that one to be bad but i still did the passenger side just to be sure. pass upstream made o2 3 steady at 440 and pass downstream nothing. so i got a new downstream sensor to see if it would change the o2 2 read out. i put it in it didn't change o2 2 readout. Where am i going wrong? not throwing any code. the reason why im concerned is cause when i pull it out the garage she runs a lil ruff. when she hit about 100 on the temp shes smooth. i leave when she' s about 110 temp she runs like a beast for like 1 mile then she feels like she lost 50hp after that. you feel a big differance. so i noticed a sulfur smell so i looked on here and people told others that it was most likely a bad o2. so i started looking at my readouts. please help finely off for a weekend. won't get time for probly another month.

[sunsetorangess]

The only 02's that matter are the front two, One on the passenger and one on the driverside, forward of the cat. The 2 sensors located aft cat just tell the computer that the cat's are working.
If your 02's are running iffy then your computer will pick it up and throw a code. Until then i would look elsewhere.
J