Saw the eCM issue coming before it became a problem. Changed the unit. Drives fine, shifts excellent. Only problem...after about a week, got it up to highway speed and the P0420 and 0430 codes came out. I know they had a flash programming for it (I have the sticker under my hood that it was performed). They werent an issue with the original ECU, but now are. Any thoughts? Any permanent fixes besides replacing the cats?