Hey everyone, 

My boyfriend and I are repairing a 2004 3.5L Isuzu rodeo. (170k miles, automatic). It has a misfire in cylinder 3, and we have diagnosed the issue as fuel injector related. The spark plugs and coil packs have been replaced, and don't seem to be the problem. Anyway, we took off the intake manifold, to find oil in places it probably shouldn't be. The 4 long bolts used to hold the manifold down were coated in oil, as were the gaskets. Does anyone know why/how this might be a problem? 

My second question is about removing the fuel injectors. Which tool is best for removing injectors in this model/year? 

Thank you very much! I am new to working on cars so forgive my rudimentary language here. Happy holidays