my car egine light is on

Question

My car check engine light is on. I took it to autozone to diagnose the problem. Code P0420 was diagnosed. Definition: catalyst system below threshold-bank 1. Probable cause are: air leak in exhaust before rear H02s (heated oxygen sensor) -bank 1. AF sensor error, fuel system fault, faulty catalyst converter. I took to emission repair shop, the gut told me that I need to replace the catalyst converter. But I just have the exhaust front pipe changed 5 months ago. I contact the seller of the exhaust front pipe, they agreed to replace tge the faulty one if i return it back to tgem. My question is that, is it okay to change the exhaust front pipe instead of the catalyst converter. Thank you all.