If the catalytic converter is clogged enough to cause a restriction, no cleaning will solve that. It will need to be replaced. Additionally, the O2 sensor is critical to engine operation and fuel economy. I suggest you do what you can to fix that problem instead of modifying the computer to ignore it.
This can help you identify an exhaust restriction.
This can help you diagnose performance issues with your engine: http://www.ericthecarguy.com/faq/solving-automotive-performance-issues