2003 Toyota Corolla Q&A

2003 Toyota Corolla Question: catalytic changed and engine light comes on. code po402, what does this mean?

different mechanics give me different answers for a changed catalytic converter. had it dx. and engine light still comes on. The last mechanic stated that i needed a double headed converter and I checked auto part store and it stated that I only needed a single headed converter and not a double headed converter? can you clarify this, please? -
Answer 1
P0402 is not the converter , it;s EGR system. P0420 is for converter below efficiency. -