P0430 Chevrolet -just replaced knock sensors and cleared code now showing p0430

Question

Just replaced knock sensors under manifold cleared that code now im getting a p0430 had replaced all o2 sensors before alrdy

Answer 1

P0430 Catalsyt system efficiency below threshold Bank 2

Is there any vacuum leaks ? The MAF air duct secured? Try this do a throttle body and a MAF cleaning see if that helps