The Lamda sensors are mounted under the car roughly just in front of the back wheels between the Cat's and the Manifolds.
If you kneel down by the back wheel arch in front of the wheel you can just see the exhaust pipes, the Cats are round and about 6"dia. x 8" long with heat shields mounted on them, follow the pipe along towrds the front of the car (about 18") and you with see the sensor (one on each side) they are round about 3/4" dia. x 1 1/2" tall with a wire leading from the top. They are quite difficult to see as the suspension mountings are in the same area.
As for the air mass controller I don't know