I am getting 0420 and 0430 codes....a few months ago I went to savanah from atlanata (300 miles each way) and the cel went off after 150-200 miles on its own and stayed off for about a week then it came back on. I am trying the G2P additive now prior to getting it replaced. When I took it to Meineke they did a temp reading and told me they were both bad.
