A bad fuel injector or clogged fuel injector could eventually cause damage to the engine if the engine is allowed to continue to misfire.
The misfiring of the engine could cause the engine and engine cylinders to overheat and pre ignite the fuel mixture which can then lead to warped engine heads and much more and possibly a cracked engine block due to overheating.
When an engines fuel injectors are dirty they will not cause enough fuel spray to get through to allow the engine to run properly.
An engine needs the proper amount of fuel spray to allow the engine to run properly and enough fuel spray must go through the fuel injectors.
If your fuel injectors are dirty then it can cause loss of engine power, increased fuel consumption, lean misfire, rough idle, engine hesitation and engine stumbling upon light acceleration, and a loss of engine power.
If clogged the fuel injectors may even cause no fuel to get through to the engine which could cause the engine to stall out completely or cause the engine to not start.
If you're having hesitation problems and misfires and the ignition coils, spark plug wires or spark plugs are all good including the distributor cap and rotor if your vehicle has them then the fuel injectors could be dirty or clogged.
You can try adding some fuel injector cleaner to your gasoline tank which will sometimes clear out the fuel injectors if they are not clogged too bad.
But sometimes you may need to have the fuel injectors professionally cleaned at an auto shop or replace the fuel injectors.