I replaced my plugs not long ago. 2003 HCH that I got used. Didn’t do anything special, just replaced them. Got AC Delco equivalent to the recommended plugs from NAPA. They were a little pricy (about $8 each) but not $13! They looked the same (tapered center electrode, etc.) Didn’t loose any performance . . . may even have gained some FE, but I don’t know how old the other plugs were (I assume they were pretty old, car had close to 100,000 at the time) and how much that affected things.

kernk