i have a 94 b18 swap in my si hatch it runs good but alot of smoke comes out the muffler wat can it be???

 

what color smoke, maybe a bad head gasket...

 

its grey smoke not black its clean smoke but.. idk

 

chances are it might be a bad headgaket or coolant is getting into your exhaust system, thats all i can think of

 

if coolant was getting into it, the smoke would be white. if the color is blueish then its burning oil. It can be ur head gasket if the colors is bluish and if its white it could be ur piston rings.

 

I also have a B18B1 in my 93 Del Sol. I just had the head shaved and a new head gasket installed due to a warped head. I had an issue burning the coolant. Now my coolant is good and it smokes like a grey. So Im not ruling out the head gasket or anything. but just throwing in some ideas.

 

Blueish grey usually means a set of rings and valve job.