Sorry, blew right past you're post about the p0430. Honestly you might get lucky with an aftermarket cat but that is very rare. Japanese cars have very little tolerance with inefficiency of aftermarket cats. I read or heard in a class somewhere that aftermarket cats are usually about only 80% efficient when new. You will get a p0420/430 when your cat is less than 80%.
If you have room for this, you might want to try it. I haven't put them on 5 or so cars with good results. because that's not legal. <title>O2 Simulator Mini Cat Cel Fix best oxygen sensor simulator made.
If you have room for this, you might want to try it. I haven't put them on 5 or so cars with good results. because that's not legal. <title>O2 Simulator Mini Cat Cel Fix best oxygen sensor simulator made.