My 96 neon has a trouble code 72, I understand that this is a catalytic converter problem. The question is how do i determine whether the converter is bad or if something else is going on like a false o2 reading or a false maf sensor reading. I just want to make sure that I definately have a bad converter before I sink the money into a new one.

Thanks

The simplest thing to do is to reset the code and see if it comes back.

Next step is to measure the voltage at the oxygen sensor on Bank 1 (the rear sensor, or the sensor after the converter). The voltage should be low and steady (~200mV, depends on the vehicle). If the voltage varies (e.g. 100mV to 600mV) then it's time to replace the catalytic converter. In fact, it would be a good idea to test each oxygen O2 sensor while you're at it