Fixing a Dried-up and Cracked Vacuum Hose

Easiest answer on how to fix it? May be best to simply replace it. 

Some cars have a lot of plastic parts on them. 

Plastic sometimes breaks, cracks or warps. Cars use vacuum systems to communicate between systems and regulate some functions. Vacuum hoses are sometimes made of plastic.

Here, this Mazda had a vacuum leak through a cracked, deformed hose, causing a check engine light and some issues - Like running lean (too much air mixed with too little fuel)

On the left is the old, deformed, cracked hose, and on the right is the replacement hose. Feels wasteful to replace the whole hose, but it’s the best we can do!