Repair manual

SULEV 2.0L TFSI Engine
34
Oxygen Sensors
The oxygen sensors were designed to minimize the
time-to-readiness for the closed-loop operation engine
management system.
By installing the broadband oxygen sensor in the turbine
housing, closed-loop operation can begin only 19
seconds after starting the engine.
Due to the risk of water shock during the broadband
oxygen sensor’s rapid rate of heating, a special sensor,
Oxygen Sensor G39 (LSU4.9), is used here.
G39 is located upstream of the primary catalytic
converter. This sensor has an additional triple-layer
protective tube.
Two type LSU4.2 nonlinear oxygen sensors are used
upstream and downstream of the underbody catalytic
converter. They facilitate natural frequency-based closed-
loop operation, and allow the primary and underbody
catalytic converters to be diagnosed for aging separately.
Inner
Protective
Tube
Hexagonal
Housing
Middle
Protective
Tube
Outer
Protective
Tube
Design of Heated Oxygen Sensor G39 (LSU4.9)