1. Remove the clamps and vacuum hose.
2. Apply both suction and pressure to the engine-side hose, and verify that air blows only toward that side.
Mazda 6 Service Manual: Location index
INTAKE-AIR SYSTEM
FUEL SYSTEM
Engine Room Side
Fuel tank side
EMISSION SYSTEM
Engine room side
CONTROL SYSTEM
...
Mazda 6 Service Manual: New standards
Following is a comparison of the previous standard and the new standard.
#1 : Diagnostic trouble codes depend on the diagnostic test mode
#2 : Controlled by the PCM
#3 : In some models, there is a fuel pump relay that controls pump speed.
That relay is now called the fuel pump relay (s ...