Hi Guys, I installed a secondary cat-bypass pipe this last weekend on my 2.7 355. After reinstalling the system, there are no exhaust leaks and the vacuum line is properly attached to my bypass valve. My valve was operating properly prior to the cat-delete pipe being installed. That being said, when accelerating, I can definitely hear the bypass valve opening. Shockingly loud...sounds almost like there is a vacuum leak, as it opens going through the gears. It howls loudly. Is this just more pronounced now that there is not a cat to muffle the sound?
ok, just temporarily wired the bypass open to see if that was truly the cause. It's not. The cat-bypass I installed was a gutted secondary pipe. Could the airflow/harmonics cause this sound?
My car is noticibly louder wiht the bypass pipes (which I install for trck days and return to cats for street driving.)
