Exhaust leak after using seafoam???

i put some in my gas tank and some i put in the brakeboster hoes. and i statered it and it smoked and the smoke started to come out from the #4 exhaust port also there was oil and some black crap all around it and leaking down the block? has anyone everheard about this happening to anyone ?

talk about cleaning out the system huh... Never heard of it but hell it might be a good thing. it isn't loud now is it

well i got a flowmaster on it but there is no nosie come from were the leak is all u can see is the smoke form the seafoam. the smoke is coming from were the header meets the down pipe

lol that stuff really cleans my cars got some more pick up after using it

well the smoke from the seafoam stop now i got a leak were the header meets with the down pipe what can i do to fix this is there a gasket that goes in between them???

i bought some seafoam for my car but dont know how to use it. where exactly is the brake booster hose. my car has been rough idling for the past couple of days. it stalled twice at my jobs parking lot.
its a 99 cavalier 2.2L

look behind the master cylander... there should be a large rubber hose, when you pull it off it should be a suction relief sound. Thats your brake booster hose.