Q: Why would my 2002 Honda Odyssey make a tapping noise when idling in park

Hello. Most of the time when a tapping noise starts on this engine it is from the valvetrain. It can be a failure in the clearance of the valves, or more commonly it is a failure in the variable valve timing system. Before tearing into the engine though I will usually change the oil. Old oil an old or cheap quality oil filter will cause this to occur also. If changing the oil does not help then you have an issue with the valvetrain. I would have a certified mechanic, like one from YourMechanic, take a look at it to [diagnose why the engine is making a tapping noise] https://www.yourmechanic.com/services/noise-from-engine-or-exhaust-inspection