Hey fellas, well I've been going through my daughter's car. Was getting misfire on number 2
Anyway, did a compression check and number 2 was low. Well I happened to remove the heat shield today from the exhaust manifold and they'res a crack starting from the O2 sensor and ending towards the pipe going to number 2. Can a cracked exhaust manifold cause low compression and a misfire in that cylinder? I'm thinking maybe that's my problem and not the head

 

No it wouldn't cause low compression, misfire yes

 

Does the crack happen to extend to the head? If not, it's a separate problem, as mentioned.

 

problem isn't necessarily the head, either. you need to do a proper compression/leak down test