there are 2 different types of fuel injectors for 2000 camry i4 2.2L depending on emissions compliance (federal vs california). check the sticker under hood (or location of upstream o2 sensor in exhaust manifold heatshield - middle = calif, bottom right = fedral), it will say California emission blah blah if that's the one, if not then it's federal.
most likely dealer was giving you the other grommet.
california injectors use additional o-rings and different grommets. here is a pic of what i'm talking about.
hope it helps.
just noticed it was your first post
welcome to forums!