O2 codes killing me!!

[Sjackson2]

Ok....so ive been getting all kinds of O2 codes recently. until yesterday.....i was getting bank 1 and 2 sensor t20 high voltage codes and a bank 1 sensor 2 insufficient code. Now yesterday i pulled them again and im getting codes for both banks sensor 1 as well! What the hell man know the tsb for the grounding harness doesnt apply to the 01's....but ive made my own engine block ground harness and installed it anyways. i have new o2 sensors for both bank rear sensors on the way....but what are the odds both of the pre cat sensors are bad now too? The truck has a lot of miles and i dont know if theyve ever been changed....but whats the likelihood of them all going bad at once? The light first came on about two months ago. Both rear sensors have spark plug non foulers on them because they were originally getting codes for cats being insufficient as well and the non foulers took care of those...but im still getting the rest 

[RainGoat]

Generally, they all go bad. It’s the one recurrent problem I’ve had. Changed out 4 by 100K, though one is still OEM & another was a replacement that went bad. Luckily, they only take about 15” to replace. Drop them from the top & zip tie to your old line, cutting off the old heads. You’ll get plenty of practice.

 

[Sjackson2]

ive already removed the rear two a couple times while making the o2 simulators for them. just seemed weird that all of a sudden the front 2 are throwing codes as well