Rattling in Infiniti i30t

I’m hearing a disconcerting sound coming from my car as of late. It’s a rattling sound, almost as if someone were shaking a can of spray paint at the same frequency as the engine. It doesn’t strike me as being a heat shield, it’s a heavier rattling, not really a buzz.

The sound usually occurs when I am above 2000 RPM, however, it does not match an RPM range or the car’s speed—it seems more closely associated with the position of the gas pedal—about halfway to 3/4. It does not make the sound unless the car is in gear and moving.

On cold starts, the engine fires and runs, but then takes up to 30-40 seconds to really get going at a normal RPM. Efforts to coax it with the gas pedal are delayed by a second or two before they kick in…

The car is a 2001 model, and has 44,000 miles.

When was the last time you changed the air and fuel filters? Have you had any CEL’s?

At that age the possibilities are endless. Most likely it it exhaust related.