Can a cracked/leaking exhaust manifold cause a rough idle?

[arndog123]

My '85 mini w/ a 22re idles a little rough. I put in new plugs, cap/rotor and OEM wires. Adjusted the valves, verified timing and cleaned out the throttlebody and installed a new fuel filter. I think there's a leak around the exhaust manifold 'cuz I can smell and hear it. Unfortunately, I can't see where. Would this cause a rough idle?

 

[85+92]

if it has anything to do with the EGR system its possible it could cause a vacuum leak.

(not my pic, pulled it up on the google)

 

[arndog123]

My 22re doens't have that pipe. I checked the EGR valve w/ a vacuum pump and it's good and and not leaking by. Going to change out the exhaust gaskets today and hopefully fix the idle issue. Ran seafoam through a vacuum line yesterday and it looks like it's leaking between the end of the manifold and the pipe that's bolted to the side of the tranny. It was quite a smoke show.

 

[85+92]

I doubt its going to help then, technically you could run open header and it wouldnt cause an issue...

have you tried spraying carb cleaner on various vacuum hoses while its running?