Mazda 626 Catalytic Converter Replace/Remove

I Have A 2001 Mazda 626 Ex V6 With 85000 Miles. Recently The Check Engine Light Has Been On. I Have Had Two Mechanics Check The Problem...

The Problem Is That Two Pipes Under My Car Are Not Connected. I'm Not Sure If They Were Welded Together Or Clamped Together. I Cannot Find...

I Have A 1997 Mazda 626 Mileage Is 97k,i'ts Giving Me A Code 421.ive Taken It To 2 Mechanics And They Have Replaced The Catalyts Converter...