Okay..... Thats gonna be fun i have to be driving for you to be able to tell. Ill try to make it easier

Only happens during acceleration when driving
Doesnt happen when idled or in neutral with rev testing
Comes from engine bay
Loud noise sounds like rumbling, almost reminds you of a Harley but not as loud
RPM seem a little high for the acceleration ratio (more then usual)
Idle still works fine
No putting or backfires
Doesnt seem to have as much power as before but im not pushing it cause the noise worries me.
Acceleration sucks to be honest(more so then usual for a d16z6)