Magnaflow Competition Cat-Back V6 problem

Discussion in '2011+ Ford Mustang V6 3.7L Tech' started by mist82, Jul 13, 2017.

  1. mist82

    mist82 Junior Member

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    Hi everyone,

    i installed this cat-back some 3 weeks ago. started off sounding awesome. deep throaty sound a very loud scream when you floor it. had some drone at about 2800-2900 rpms but nothing that bothered me. here is my issue:

    it sounded great until about a few days ago. sound all of a sudden changed from deep and throaty, to thin and raspy on higher RPMS. nothing changed on the car in the meantime.

    i know all these exhausts need a bit of time to break in, but to loose the sound like this? do i just have a pair of bad mufflers or what is going on? its just not loud any more. and yeah, since it isnt, drone is gone now, which i rather have it being loud than like this.

    anyone had a similar experience?
     
  2. 01yellerCobra

    01yellerCobra forum member

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    Go over the connections again. Something might have loosened up. It's amazing what a leak can do.

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  3. mist82

    mist82 Junior Member

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    thanks. i was planing to get under it this weekend and check it out. its only 4 connections, so its not that much effort. ill see if something moved or needs tightening.
     
  4. Iceman62

    Iceman62 Bullitt 6005

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    You need to re-torque all connections/clamps after 50-miles...my son's muffler clamps loosened up during break-in. Once re-tightened, no problems since.

    Also, I always use HT silicone on all exhaust installs (e.g. liquid copper)...creates a solid/air-tight seal to prevent dreaded exhaust leaks.
     
  5. mist82

    mist82 Junior Member

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    yup, thanks for the tip. i will try that as well. i got under and re-positioned the mufflers, and i believe i got the original sound back. it might have been a loosened clamp, but it seamed pretty tight. what i did is pull the mufflers out a little more so that the tips stick out more. apparently they both moved since they were originally installed somehow.

    seems much better now, but i will most likely add some silicone to have it air tight.

    thanks!
     
  6. John Linck

    John Linck Junior Member

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    I'm glad I found this thread. I had the same prob, also with an aftermarket muffler. And the guy in my local shop told me, that something's wrong with one of those resonating plates, so it has to be either warrantied, or he can cut it and fix what's inside... Now I guess I will check the connections first and will silicone the connections first, and then we'll see how it goes...
     

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