Hello fellas, first time posting. For once it seems I cannot find the answer I need in a previous forum.

I'll start off with saying, I don't ever recommend purchasing DAVICO Converters from RockAuto. About 6 months ago I lost my left side Catalytic Converter on the E55 AMG. My Indy mechanic recommended
DAVICO converters from RockAuto and so I bought one. Not only did it not fit right but the secondary cat was bad right from the get go. I sent it back to RockAuto under warranty and they sent me another one. Lo and behold this one fits even worse than the first (mechanic had to modify the sway bar to clear primary cat) and within a month of driving on it, the secondary cat fails yet again. RockAuto offered me a refund for the defective cat, however they would not send a replacment this time in fear that the issue would persist no matter what. Sending back the Cat for a refund is not a viable option for me. By the time I get it removed from the car, shipped off to RockAuto and source another converter from somewhere else, I'll have spent way more money replacing this damn converter then I will get back from RockAuto.

This brings me to my question: I'm going to have the Secondary cat gutted on the left side. In doing so, do I need to gut the right side too? My mechanic seems to think that it shouldn't be too big of a deal if only the left side is gutted, however I am hesitant that this could lead to issues down the road.
Its worthy to note that the car already has a muffler delete. Ive surfed the internet and can't seem to find anyone who has only one side secondary cat removed. What's the worst that could happen running on a single secondary? If I do gut them both, how loud is the car going to be with the muffler also gone. Any suggestion on aftermarket mufflers that might help with this? All advice is greatly appreciated.

Thanks for reading. At the very least I feel it was worthy to let other E55 owners know to avoid these defective DAVICO Cats.