Usa models are equipped with an additional system with an evaporative emissions canister that prevents fuel fumes from being discharged into the atmosphere.
The breather hose (4) is connected to the canister filter (1); when the fuel has been filtered, it is returned through the hose (2) to the horizontal (a) and vertical (b) intake manifolds via the hoses (2a) and (2b). Drainage pipe (c) and the hose (5) vent to the ground.
For correct positioning of the connection hoses consult the indications given below.

Evaporative emissions canister
Removal of the evaporative emissions canisterEngine temperature sensor
Introduction
The engine control system on the diavel uses a sensor that measures the
temperature of the coolant (engine
temperature). This sensor has a resistance of ntc type (negative temperature
coefficient), that reduces its own value
when the temperature increases. The engine temperature ...
Absolute pressure sensors
Introduction
The engine control system of the diavel is equipped with two absolute
pressure sensors, with one connected to the intake
duct of each cylinder (map 1 cylinder 1 - horizontal - map 2 cylinder 2 -
vertical). They are used by the control unit to
determine the quantity of fuel to be ...
Removal of the exhaust system
Remove the silencer, as described in the paragraph "removing the silencer" of
this section.
Loosen the screws (28) and remove the exhaust by-pass valve cover (27).
Turn the exhaust valve pulley (a) to facilitate the throttle cable (25)
output.
Release the end fitting (b) of the cable ...