2011 Chevy Equinox keeps throwing code

I have a 2011 Chevy Equinox & it keeps throwing a code for downstream 02 sensor. I’ve recently replaced the catalytic converter, upstream & down stream 02 sensors yet it’s still cutting out, & dying on me when I accelerate from a stopped position & throwing codes. The code is always for a downstream 02 sensor but both sensors have been replaced 3 in the past 7 months

What’s the exact code?

Tester

A family friend owns a garage & he’s the one that told me the code. It said downstream 02 sensor on the screen but I’m not sure what code was

4cyl motor?

Yes it is, I ended up contacting Chevrolet because my catalytic converter keeps falling off & along with the codes my car dies whenever I put it in gear & push the gas. They told me there’s been recalls for many things on this vehicle & they’re sending me to a dealership to have diagnostic ran & repairs made

That sounds like an air leak or a faulty maf sensor to me. Since your cat falls off the exhaust system is probably leaking. Modern engines simply won’t run well with a leaky exhaust system. So fix that problem first.