at (autozone) the guy told me what u want the rear manifold sensor or you want the front manifold sensor he told me that the rear manifold one is for the cat and he told me to order 2 front manifold o2 sensors whats the deal dont i neeed the front and the rear o2 sensor.

 

There is 1 O2 sensor for EACH bank of cylinders and then there is one after the main catalytic converter. 3 total