Nissan Repair: Automotive, Catalytic Converter, 2003 nissan altima, nissan altima

Question
I have a 2003 Nissan Altima that was built in 12/02, and it needs a new catalytic converter which is attached to the exhaust manifold. The 2003 Altimas built after 2/03 have a different catalytic converter which is also attached to the exhaust manifold. My question is: Is it ok to use the catalytic converter specified for the models built after 2/03 on mine which was built in 12/02? My assumption is that the converters specified for those built before 2/03 are not to be used on those built after 2/03 but not necessarily vice-versa.

Answer
Harry,

If it will physically fit you can use it.  The big thing is that the car is OBDII, on board diagnostics II, and that means that the car will know if the converter has been removed.  So, as long as you have a functioning converter with an oxygen sensor both up stream and down stream you should be fine.