becuse you have 2, o2 sensors did u read the very first one?? if u dont kno were the rear exhaust manifold is its below the rear valve cover by the fire wall
1st, pull the o2 sensor the one on the rear exhaust manifold
2nd, then take it for a ride with it out
3rd, if you have your power back this is your problem
4th,go bet a cat
5th just cuz it dont make any sounds wen you tap on the cat does not mean its good, and it will not be glowing red thats only if its not runnin rite dumping raw fuel in the converter