Other members of the club may have more of a technical view to offer but we had similar problems with our 2003 (late 2002). Several years ago, a cross tube ruptured in the CAC--no reduction in power but you sure could hear it. About a year ago, we had an exhaust manifold gasket leak. Again, you could hear it as the leak was near a cylinder exhaust port so there was a pulsing sound [and a black carbon mark on the EM]. In yr case, I dont see any causal relationship between the EM gasket leak and a possible CAC leak. Seems that in either case, a combination of visual inspection and a check of the boost levels [via computer?] would determine if you have any "charge air" leaks....
2003 40' MDTS
Garden Ridge, Texas