I ran Kenji catless for about a month then went to a 5". (Yeah I know exhaust exit still 3.15") No issues with the Kenji, no cel. Sounded slightly better than the AA. Not really hat raspy too, may by due to my Valvetronic exhaust. You will notice the smell. It doesn't bother me tho.
Wheels still available but it'll cost about $200-$250 to ship coast to coast, its about $50 each wheel from my last estimate unless you can find cheaper.
Are you still not getting any E reading on the dash? Did you make sure your connections in the body domain controller are correct?
Here's their instructions: https://bootmod3.atlassian.net/wiki/spaces/BCS/pages/2592112641/BM3+Flex+Fuel+Kit+Installation+Instructions