What else could be going after relacing the catalyst converter and oxigen sensor

Why would you change the catalytic converter without performing necessary testing? That's very expensive – – typically codes that relate to oxygen sensor performance do not implicate the converter as a possible failed part. Without knowing the specific codes or monitoring the data stream with air and fuel mixtures, it's impossible to know anything. I would recommend you have your vehicle evaluate it at a local shop near you that can give you direction. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops