2002 Malibu #3 cly misfires on v6

Did you visually check for spark at the spark plugs on that cylinder? Did you use a noid lite and check fuel injector pulse on that cylinder? The cylinder needs three things, fuel--spark--compression at the proper time. You need to do some testing. Are there any driveability issues, idle or driving down the highway?

I just wanted to add, any electrical component, if the wiring circuit has a problem, replacing the part won't fix it.

Another possibility is low compression on that cylinder. Check compression.