Engine Car Makes Weird Noise

[arena314]

Just got a new clutch in and all and also since my tail pipes were un even I just told him to cut them off right before the axle so it's mufflers then basically dumped right after. I also installed a bama tune and new intake bc my old one was junk. I can't remember if I always heard it or if it's just bc my car is a good bit louder now but when I'm at a steady rpm like 3000 or so my car makes a weird noise almost like a knocking noise and idk what it is. I know its not like a rod knock bc if I have the car at idle and hold a steady rpm I don't hear a thing and everything looks good the oil and all. My car vibrates alot due to the loud exhaust so Idk if it has something to do with that or not. Any ideas? Every once in a while I'll get a misfire code so idk If I need new coils and wires or not. Idk do you guys have any ideas? Could it just be the car vibrating? Thanks for any responses