what's the benefits of headers? If a guy puts headers on will the vehicle pass emissions?
Headers increase power through exhaust "scavenging". That is the exhaust flow from one cylinder "sucks" the exhaust out from another cylinder due the bernoulli effect(increased velocity reduces pressure). They are prone to all the problems listed; cracks, leaks, etc.
Yes, providing the headers are not leaking they will have no effect on emissions.
