Okay, first off, if you remove your catalytic converter on a 2G you may get a check engine light (CEL). However to correct the problem, you do not need to "get a new ECU". You can either rewire the 02 sensor, check the vfaq's,
www.vfaq.com, for instructions. If you don't want to do that, you can simply unscrew the 02 sensor after it gives the CEL and let it sit in air for a couple hours. When you put it back in the ECU will clear the CEL could stay gone anywhere from a day to months. You could get a datalogger or pocketlogger to clear the ECU (what I do) the pocketlogger costs $175 and uses your existing PDA. Lastly, you could go and buy a $1500 complete standalone engine management system and program it to permanently ignore the bank 1 02 sensor number 2. FYI.
Peace