When I rev up the motor and let off the gas I get a rattling knocking noise

What is your question?

Every time it makes that sound when in park no load but it's got no loss of power and no misfire any ideas. TY 2002 Nissan maxima se 3.5 L dohc v6

What makes this problem better or worse?

it's worse when it gets to operating temp

How long has your 2002 Nissan Maxima had this problem?

2week's