Im having to replace the Catalytic Converter on my 2001 Civic EX with the D17A2 engine. The cat that is on there now is one that sits under the middle of the car and the O2 sensor plugs right in to it back there. After looking up a replacement, the one they show is the cat that is part of the exhaust manifold up in the front of the car. So does this mean to replace the cat I have to relocate it up front along with the O2 sensor? This is only because I live in california and that is the only one they show being CARB compliant.....

 

Did someone modify the car previous to you owning it? From what I have seen all 01-05 Civics would have the cat up front and built into the manifold like you are looking to buy now.