Tonight on my way to my buddy's house, I hear a loud KATONK sound underneath my car like something bounced around down there, and then the exhaust got loud. Didn't feel like I was losing any power though.
I got to my friend's house and had him rev it a little bit while I looked under the car and I found it.
There's a little bung on the Driver's side of the high-flow cat. It looks like something's' supposed to screw into there, and I'm guessing that's what flew out of my exhaust.
Does anyone know what belongs there? An 02 sensor or something? I need to get this fixed.