Here's the issue , i just change my exhaust (Apexi N1) to OEM. Ever since i change it i been getting rattling sound for about 5 sec from a cold start. And ever since then i been getting black dripping from my exhaust. I need some help please?

 

Maybe you didn't put the donut gasket back in?

 

haha... ok heres one, and this happened to me. Check your o2 sensors, trust me. those things if they arent tighttt they will come out. and when you start up you will hear it rattle pretty damn bad, it wont fall out, but it will sound horrible. Also, the black crap, i had mine do that for a while aswell, its carbon built up in the exhaust, and it starts coming out, touch it, and smell it, odds are its just water and carbon (turns black), mine will spray across the driveway if i rev it until all the water is evaporated.