[dman007]

I am not an expert on the four cylinder motors since I have a six in mine however, I helped my brother recently replace the injectors on his motor and it was very easy. Each injector has one nut holding on a reatining ring which holds the injector in place. You will also have to remove the electrical connector and the fuel line from the fuel rail. There are two seals on each injector. One on the very end and another larger seal where the injector goes into the head. As far as replacing them all, I don't know. I know there is a test to see if your ijectors are putting out enough fuel. I believe you have to have the injector out of the motor but hooked up. You then measure the fuel output over a given period of time to make this determination. I am sure someone else can better give you these instructions. Good luck.