Metal grinding noise when stepping on the gas

When I first step on the gas, there is a grinding noise which last for a couple of seconds. It happens each time I stop and go. Sounds like metal parts rubbing against each other. Any help would be appreciated.

Year, make, model,auto,5sp

2005 HONDA ODOSSY TOURING AUTO

Possibly a rattling heat shield on the exhaust. This is generally not a serious problem and more of an irritant than anything else.
It’s usually pretty simple to do a work-around on a shield rattle and quieten it down without spending a bunch of money.

If it is not a heat shield, I would start looking at motor and trans mounts.