For those with the 2004. 5 models with the 4 inch exhaust and cat converters--- Has anyone installed a Muffler bypass pipe like the one Geno's offers? Did you have the "drone" and was the noise level reasonable?. Did the EGT's change? Any seat of the pants differences? Just wondering what improvements/changes to do. Thanks for your thoughts - this is a great place to get information. WCPoe.