1998 Toyota Corolla

I have the same car and had to replace the full Catalytic converter to clear it. I ordered one called a Perfect Fit which will allows engine to breath much better and should last. Meineke also replaced both O2 sensors at the same time since they were all plugged up. Almost $900. Total. There are some cheaper ones but they won't last as long. So you'll have to decide how much longer you will run this car.
Good luck, Eric