Hi everyone, ive had this truck for about a year and half now, its a 5.7. Put a different engine in the truck after I bought it, went thru it and resealed it before I stuck it in. Started having an issue the beginning of this year with a code p0430. Replaced the downstream sensor for bank 2 and it didn't do anything. Catalytic convertor reads about 125 degree warmer coming out as well as the driver side also. I compared the two. Truck has 285's and gets almost 16 mpg. Code keeps reoccurring and I'm tired of looking at it and erasing it. just not sure what else to check. thanks for any info on what to check