From a latest post it seems some DIY are having problems checking for a bad injector. It is really not that difficult. One tech recommended warming up the engine and removing fuses and draining the pressure from the fuel system. None of this is necessary to check the injectors, if they are accessible it doesn’t hurt to warm up the engine for a few minutes but in most cases by the time you gain access the engine has cooled off. It is necessary to remove the fuel pump fuse and drain the pressure if you are going to replace the injectors or remove the fuel rail.The simplest method is to listen to the injectors with a stethoscope if there is a bad one it usually will have a different sound you can also use a long extension or screwdriver as a stethoscope but this will not work as well and a stethoscope is cheap. This method will find a bad injector but will not rule out the possibility of a defective one as they do not always have a strange sound. You can also ohm the injectors at the connector that feeds all the injectors easy to get to and you can usually determine which bank the bad injector is on thereby possibly eliminating some unnecessary parts removel.Here again will usually locate a defective one but will not eliminate the possibility . The only positive method is to gain access to the injectors and check them individually I won’t go into the readings here as they vary by manufacture but usually the defective one will be way off from the rest. Be careful I have seen many with several defective injectors. If you have access to a lab scope this is an excellent method also cool to watch the injectors fire. A scope with a burn time option can also find a defective one . I know injectors are expensive but think about replacing them all as with plug wires sure as the sun will rise in the AM another will go bad soon after your repair is finished. There are several aftermarket suppliers and remans are an excellent replacement choice.