My 01 SS threw the P0420 code(low efficiency bank 1 cat) and I reset it only to have it come back after about 5 heat cycles. I know there is a recall on the cars that pull this code, but I did change something afew days ago. I have the sts turbo kit and am getting ready to install it and 1 thing that you have to do is extend the maf sensor about 18 inches. They give you crimp connections in the kit which I used and they are pretty tight, but may be causing a voltage drop. So Will a voltage drop from the maf cause any engine codes besides low maf voltage A code which I'm not getting)