I have a 2005 Chevy Aveo ls hatchback and i just got a check engine light for the code P0420. Im guessing my catalytic converter is going out or it is clogged up. the pipe is all rusted and the catalytic converter on it now looks kind of like it has a wire mesh/honeycombed look to it. Would it be possible to just replace the pipe and catalytic converter with just a pipe or does my aveo need a little back-pressure? If i was to replace it with a straight pipe then do i really need to O2 sensors? Could i just get a universal catalytic converter or does it have to be made specifically for my vehicle? I dont have much money to be spending being that i have no job and im only 17 so the cheapest route possible would be best unless it will put strain on my aveo and cause it to have more problems in the future. Thank you so much for reading and helping me out in advance!