Originally Posted by mts

I tried to search this thread with no luck but I figured someone might know. I installed my FI exhaust a little over a year ago and I did FI high flow cats are the same time. Lately my wife has been driving the car a little more and asked if there was a way to easily take the exhaust volume down just a little.

If any of you have run an FI exhaust with and without the FI HFC's, does it make much difference in sound? The HFC's are a bit of a pain to install/uninstall so if the difference is negligible I probably won't bother trying the swap.