I am replacing the catalytic converter but had to grind the bolts off. I've been having some trouble finding the bolts for the flange on the engine side and exhaust side of the converter. Can anyone tell me sizes / types or what to replace the bolts with?

Any assistance is greatly appreciated.

 

Look up the parts via Majestic Honda or other Honda online parts catalogs.
Hard to give you the correct numbers without knowing which engine your car has.