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ISF Cat and Resonator delete... Questions

7691 Views 4 Replies 2 Participants Last post by  AHI
Last night I took out the secondary cats, and the little muffler/resonator that was after it, and welded in some nice piping... I honestly thought the car would sound much different, but it really doesnt...

Do I have to bypass the rear mufflers too to get some real noise? Should I worry about back pressure, or lack of it? I'm a turbo guy, and this is my first N/A car... so not quite sure what the rules are as far as back pressure.

Thanks !!!
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I remember reading a thread on here that someone did a delete on the mufflers and rear cats. I can't remember if they did any dyno testing though after. I'll try to search a bit later when I get some time and I'll post if i find it.
here is another.

Do a quick search for "muffler" and you will find a few topics on the discussion.

Good luck.
I removed secondary cats, mid muffler, and two rear mufflers, and installed a straight pipe.... WAY too loud. Put the factory mid muffler back on, and it is much better, but there is a little drone at 2,000 rpms and 3,000 rpms.
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