So recently my exhaust has been giving a rattling/scratching noise on start up and mild acceleration.
It goes away on harder acceleration and a few seconds after taking off from a stop.
I checked every bolt from the headers all the way back and tightened them up. I'm positive it's the exhaust because I haven't made any other changes.
I checked the pipes and hangers for the mufflers and everything is solid. My mufflers don't really have any baffels/insulation so it's not that.
The only thing I can think of is possibly the material within my high-flow cats dislodged and is rattling around in there at a certain vibration frequency down low.
Any ideas? I'm going to call BBK and see if they will send me a set of cats under warranty, but I may be going with MAC Off-road Pro Chamber Shorty Mid-Pipe 21205 (11-14 V6 w/ Long Tube Headers) - Free Shipping
instead. Less raspy and I don't have to worry about cats lol
2011 V6 Race Red - Airaid CAI , BBK 73mm Throttle Body, 3.73 FRPP Gears, BBK Longtube Headers , BBK Off Road X-Pipe , Borla ATAKs , SR Performance Strut Tower Brace, MPT 91R Tune, Powerstop Rotors and pads, JLT Oil Seperator, Koni STR.T Struts & Shocks, Eibach Pro Line Springs, BMR Adjustable Panhard Bar, J&M Caster Camber Plates, Mickey Thompson Street Comps on 19" Laguna Seca Hyper Black Wheels, Several other aesthetic mods