When Should My Injectors be Replaced? If you own a truck with a diesel engine there are many different reasons why you experience a When Should My Diesel Injectors Be Replaced. If you truck is having an Engine Misfire the easiest thing to do is take it to a shop that can hook it to a scan tool capable of cutting the injectors out 1 cylinder at a time and see which cylinder is Misfiring. Another reason you may replace have to replace the Diesel Injectors in your truck is if it is Blowing White Smoke at an Idle. This may be an indication of the injectors leaking into the Cylinder and would need the injectors replaced. If you are getting a CHECK ENGINE LIGHT that turns on in your truck with a code P0087 that is harder to diagnose what the root cause of the problem may be. Depending on the model of the truck you need to have the OEM scan tool to be able to set the rail pressure at a DIAGNOSTIC pressure so that you can do a Fuel Return Flow Test on your injectors. If the return fuel amount from the injectors is out of spec, we have to cap the injectors off one at a time to see how many injectors have failed. If you are wondering Are My Diesel Injectors Leaking give us a call and we would be happy to look at your truck. We work on all truck from Heavy Duty to Light Duty Trucks.