Recently my car had some build of repairs needed done on it. 3 days ago I had the brakes and rotors replaced and the oil changed. We had to order new sway bar links because mine were busted and made a very bad creaking noise. Those were replaced today as well. The BIG thing I needed done however was I had a gas leak by the gas tank and it ended up being the pressure line cracking from the fuel pump. Wasn't a bad leak but a fuel leak none the less my fuel economy wasn't decreasing. Anyways the fuel pump was replaced because it comes as a whole with the hoses for the fuel lines. Lastly had my air filter replaced because it hadn't been replaced since I owned the car 20,000 miles ago. On my way home I got on the car as I normally do when I hit a good straight stretch and the dash seems to be rattling slightly and it almost sounds like I'm hurting the engine instead of 'letting it breath' its just something new to me. Could it be possible that the new air filter is allowing it to breath more? Or that the new fuel pump isn't putting out as much fuel pressure? I see no significant change in performance other than the noise and engine sound.

 

Also the rattling starts at around 3k rpm and stops at 3500 or 4k. And now its stopped for a good bit but here it every other good hit on the gas.