I have a plastic lid that fell off a five inch hole on my engine block right under my airbox dont know whats that lid is or should it be sealed? Also I'm throwing a p0440 code ... and my biggest issue is a rattling wobbling sound coming from the front of my motor but the noise is tricky ... it seems to be near my cam shaft pulley? It's been getting worse also since I replaced my alternator? Could it be that lid making that noise considering I had to sit it back over the hole it was made to cover? I'm wondering if it was once sealed over the hole?any help is greatly appreciated?