2000 Isuzu Rodeo

Hi. I just bought a used 2000 Isuzu Rodeo, and it runs fine. The only thing that stands out is that when I accelerate, I hear a rattling noise, presumably from under the front side of the vehicle. It is not horrendously loud, but I can hear it when I have my window open. Also, I am going to take the vehicle to my mechanic for a maintenance overview. Any advice? Thanks.

Heat shield on cat,rock in heat shield.Hopefully it’s is not a engine “ping” or “knock” you hear,the phrase “on acceleration” concerns me.