Q about off-road H &X pipes and O2 sensors
 

I have heard that once you get rid of the cats your O2 sensors do not work properly anymore. I take this for the truth because mine are all messed up. What do you guys do? I have heard about welding a small piece of metal behind them to bring the back pressure up but that didn't seem to work for me. Let me know what I should do or is it another one of those things to ignore while scaning for codes?
thanks
Chip

my car runs fine with the off road H and I don't ever remember pulling codes for the O2 sensors
As long as it runs fine I think the codes can be ignored, just my opinion

Removing your Cats will not screw up your 02's, only age does that, removing the cats will make the car run richer.

I am getting a
91 Heated Exhaust Gas Oxygen sensor circuit indicates system lean (left HEGO
41 Heated Exhaust Gas Oxygen sensor circuit indicates system lean (right HEGO

Plus the good old 34 EVP voltage above closed limit (SONIC)

Both sensors have been replaced. Could they both be bad? Where do I go from here?

Chip