I have the same one. Noticed a terrible whistle when I really got on it. Complained to Magnaflow, and they said it was "turbo whistle". I cut off the twin tips, and installed an oval tip and it sounds SOOOO much better; no more whistle and more of a deeper growl.
Also, I would recommend using Fluid Film and use the straw to spray inside it. Clings to metal surfaces, but breathes and keeps water away. I also live in Wisconsin and will be coating the underside and inside all sorts of spots I can to keep the salt away. https://amzn.to/3RA2w1i
Not making anymore, but I'll provide some instruction.
So for the pins you need 10 of these (order more than that for screw ups): https://www.mouser.com/ProductDetail/538-560023-0421-LP
1 Female connector: https://www.mouser.com/ProductDetail/538-34791-0080
1 Male connector...