I didn't disconnect my battery and have had no probelms in the 4 days they've been on. No smell, quicker reving, a little more sound with the windows down but still pretty quiet with the windows up.

I took a hammer to the heat shields on the car but didn't have to touch the cats. I just hammered them flatter and more to the contour of the cat. I did both sides, with a little more done to the drivers side. So far under different conditions I have had no rubbing or rattling at all. The only issue I had was the mounting bracket didn't line up very well. Maybe I should have bolted it up loosely before I finished cranking down the cat bolts.

 

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