96 blazer, have replaced the o2 sensor directly in front and directly behind the catalytic converter. My question is, are there o2 sensors in each header leading down to the catalytic converter, making a total of 4? I have gotten some conflicting information and the chilton manuals are not clear on the number. Thanx

My 96 Blazer does have 4 o2 sensors. 1 in each header, one before the cat, and one after the cat.

on 96 and later models came out with the OBD2 computer system and they all come out with 4 sensors unless its a four cylinder or something like that. My question to you is why did you change an O2 sensor?

I agree with "allaboutchevy" mine has four as well. i have never seen the case to replace them all at once. you know you can test those things.

96 blazer, have replaced the o2 sensor directly in front and directly behind the catalytic converter. My question is, are there o2 sensors in each header leading down to the catalytic converter, making a total of 4? I have gotten some conflicting information and the chilton manuals are not clear on the number. Thanx

There are 4 O2 sensors on your vehicle. One on each bank, a pre converter and a post converter.
Why did you replace the sensors?