Failed emission:

• Performance lost
• Engine does not reach full RPM
• Increased fuel consumption
• Poor idle
• Surging an bucking under light throttle
• Smoke from the tail pipe
• Detonation which can lead to catastrophic engine failure
• Pollution

Leaking injectors will cause:

• Increased Fuel Consumption
• Poor Idle
• Fuel odors inside and around the car
• Hard Starting
• Poor Emissions
• Oil thinning which can lead to catastrophic engine failure
• Hydra lock

External injector leaks is a fire hazard and can not be fixed. Injectors with external leaks must be replaced.