I was shopping around for an universal catalytic converter for my exhaust setup since my old oem catalytic converter won’t bolt up to it due to different piping size. So I was wondering for those running universal catalytic converters, I’m assuming trying to match the exact dimensions of the stock catalytic converter is recommended ,but would running one smaller(guessing won’t pass smog as well) or bigger(restriction of flow?) have any negative issues?
I’m currently looking at magnaflow universal cats. Trying to stay smog legal as well.