Car: 1999 honda civic LX

Mods: none, 100% stock

Miles: 140k

The cel was on so I pulled the codes and it would say that both the p[rimary anbd secondary O2 sensors were bad. So I bought new ones, replaced them, cleared the codes.

The cel came right back.

Same codes once again.

I have no idea what could be wrong.

I'm thinkoing maybe the cat is bad but I'm asking for others opinions, maybe you had a similar problem in the past.