Discharge line
You need to check for a clogged pipe .
if it's plastic pipe you can just buy a glue cap and glue it on. If it's galvanized or cast iron pipe you can use a gym cap, (arubber cap that comes with a hose clamp). Just put that on the pipe and tighten it down firmly. this will prevent any sewer gas from coming out of the drain.
The sink drain is plugged,or you have the dishwasher hose hooked up in wrong place.
Call a plumber!ANS 2 -If you mean the water supply pipe for the dishwasher, then it's easy to totally disconnect the copper at the dishwasher connection and at the shutoff valve. Replace it with a flexible rubber, SS braided one. Purpose built for dishwashers to allow easy movement. -Available in HD or ' big box' stores. less than $20
Buy a branch connector
There is purpose made braided SS Anti-Burst flexible line. It comes in 6 and 8 foot lengths
Both dishwasher and toilet are sharing the same outlet pipe/drain it is possible when disahwasher is in use it is blocking of the drain somehow so the toilet water has nowhere to go - you need to have a look at the outlet pipe of the toilet and dishwasher the problem lies in a conflict there.
Yes, the air vent (air gap) is very much required!! It prevents water from traveling from the sink drain pipe or garbage disposal and into the dishwasher.
there are 2 preconverter located at each exost manifold ,then under car comes Converter with a pipe ,then comes Intermed pipe...however ,in the book i got the preconverter are called catalit converter
It is normal for dishwashes to discharge below the sink into the "S bend" (otherwise called the trap) this trap is there to stop the smell from the drain coming into the house. Often there is a spigot on the trap onto which the hose from the dishwasher fits, so if this is how yours is done you will find a roughly 20mm hose under your sink coming from the direction of the dishwasher and going into the side of the sink trap, also you will hear the waste water discharging into the trap as the dishwasher cycles.
The pipe has plastic or rubber gaskets in them at the joints. Sometimes they wear out or the pipe gets bumped by moving something under the sink, moving the gasket out of place.
The tube under a car is two things: 1. The exhaust pipe comes from the engine to the muffler, and 2. The tail pipe goes from the muffler to the rear (usually) of the vehicle.