[mybeetlejuice]

ok here is my problem>
3weeks my bug started running very bad,misfiring and at times no power, check engine light is on went to auto zone to read codes. It said po300, po301,and system 2 lean bank 1. So I replaced spark plugs and coil packs,changed my o2 sensor. Today I got a new catalytic converter. and guess what.. about 1 hour later check engine light came back on ( car is running good) , went back to auto zone to have codes read, and it is saying exactly the same codes that I just had before i did all the repairs.. Can some one please tell me what is going on.