Nope.Do I need to remove the injectors if i'm just changing the plenum gasket?
You don't have to but if they are frayed you should. The aacv vac lines are 1/4" id. You can use colored ones but I would stick with the molded oem hoses because they are constructed in a way that keeps them from collapsing under vacuum.Do I have to replace all the lines?? What size are they? so I can replace them with colored ones.
Yes. You can do this without disconnecting any of the vacuum lines.Ummm when the plenum is unbolted. Can you just pick up the plenum enough to slide out the old gasket and slide in the new gasket?