i have a LS1 in my custom car with a factory wiring harness that was modified. I didnt pull the motor or harness so i dont know if it had 2 02 sensors or just one. I only saw the one 02 sensor on the header for one bank. But for the other bank was the factory o2 sensor on the cars exhaust? or did it just run the one o2 sensor? Im not talking about after cat. o2 sensors either. IM ONLY TALKING ABOUT BEFORE CAT. thanks for your help guys

this was out of a 2001 trans am

 

Yep it's correct the way it is.

 

If you want to know about before cat, then originally, it runs 2 o2 sensors before the cat