Hi I have a Dodge Caravan 1998 and I have to remove the upstream sensor which is located on the manifold on the back side of the motor, which is under the fire wall, does anybody know the easiest way to get to this sensor without taking out too much stuff.

I'm unfamiliar with your vehicle, but I would see what I could easily remove to increase access. For example, you may be able to remove the air vent cover below the wipers (as if you were going to replace the cabin air filter). Then, you may be able to remove several screws inside and remove the lower cowling. This approach may open up all kinds of rooom. Another approach may be to remove a wheel and fender liner. Be bold and don't give up. If a professional mechanic can do it, so can you.