Having issues with codes. I'll start at the top. Yesterday check engine started blooming, went to auto parts and they put diagnostic on it and said it was a misfire. Car was sounding rough while idling.So I changed spark plugs and the problem stopped. Disconnected battery and check engine light went away. Next day drive to work about an hour on the ride check engine comes back on not blinking though. I did oil change and air filter and oil filter change as well. Went back to auto parts store and misfire is gone but I have 83-1, p0420, and p0430 now. The 83 is ecm and the other two is catalytic system below threshold in bank 1 and 2. Can anyone help with info.