Gee, I thought the GEN IV still had short runs of plug wires.
The first thing is to bond the exhaust system in at least three places. The hood needs to be bonded as well. If you don't know about this, visit my web site and look under bonding.
If it does indeed have COPs, the they can be shielded, but from my experience, it won't help much. What does help, is new plugs. After about 30 to 40 k miles, the gap widens enough to increase the noise drastically.