I have a 94 5.0 with all factory exhaust and i was going to put some lt headers and looked uder and noticed that i have two cats. One where both manifolds meet then it goes back about a foot or some then there is another cat

 

So I'm trying to figure out how many cats. I have 1996 Ford F-250 5.8 trying to find where is the o2s located cause I'm trying to run true dual straight pipe and I want it as loud as possible

 

You do know you just posted in a 1-1/2 year old thread, right?

O2 sensor is in the Y pipe, ahead of the Cat. If you want loud, just cut the exhaust off in front of the Cat and put a single exhaust on it to just in front of the right rear tire.. Instant loud. Your neighbors will love you, too.