So i knew these cars had o2 problems and i have gotten PO420 twice. But i always had a bad rattle under the car and when i hit the cat, i could hear it so i assumed it was the cat. Today i was under the car and noticed when i hold the o2, rattle is gone. removed o2, i can hear the inners of the o2 rattling. I ordered a new one should be here in a few hours. Hopefully that fixes the rattling noise

This happen to anyone else???