1997 Saturn Catalytic Converter

I have a 1997 Saturn SC1 1.9L with 80,000 miles with a bad Catalytic converter( failed emissions) and O2 sensor., can I replace it with a Universal replacement. Pep Boys told me they have to order from Saturn and it is $1000.00 and I can not use a Universal because it is not strong enough to put out the check engine light? Sounds strange to me, What do recommend?

Thanks D Dunn