Replace the wire set (spark plug wires) and the plugs (gap to .054"). That should do the trick.
About $100. DIY job.
Bank 1 (passenger side), Bank 2 (driver's side)
Before you remove the spark plugs, Shop-vac out the recessed holes, 1/4 turn on all spark plugs, and vacuum again to remove any more loose debris.
Do not overtighten the spark plugs. Snug and a little more is what I use to determine torque.
Check your work. Enjoy the beverage of your choice...
, you've earned it.