In this video I am going to show you how to diagnose a dirty or faulty fuel injector. Fuel injectors could be very expensive and also a lot of times hard to get to which makes being able to accurately diagnose a dirty fuel injector very crucial. I will also show you a trick you can use to rig up a cheap fuel injector cleaner that could help you clean your fuel injectors. Whether you are having lean codes (P0171, P0174) or missfire codes and you've ruled out an ignition missfire, you need to watch this video so you can diagnose fuel injector faults if any.