There are many materials that will serve to carry the air to the sensor, but there is a very important reason for using foam tubing. The foam tubing will conduct very little heat through the wall of the tubing. This way you get a MUCH more accurate air sample to the sensor. Vinyl, plastic or other materials will cause the sensor to measure the temperature of the hose, rather than the temperature of the air sample going through the hose.

This is why MB put a foam hose on it in the first place. They just didn't have a very durable material.

Have a great day,