My dad called me up and says his 2005 5.7L Ram has a part-throttle stutter. Not a bog, but a stutter. I told him to check the plugs (all 16 of them!), as they have never been changed. It seems like a single-cylinder ignition issue to me, which can be tough to troubleshoot if it's not an obvious spark plug issue. So my thoughts are coil packs or spark plugs. Hopefully it's not the problem I had with one of my cars: a plug hole full of coolant.
What other ideas do you all have?
Unfortunately I don't live near my dad, so I can't be there to help in the troubleshooting process.