Hyundai Tucson: Engine Control System / Heated Oxygen Sensor (HO2S) Description and Operation
Heated Oxygen Sensor (HO2S) consists of zirconium and alumina
and is installed both upstream and downstream of the Manifold Catalytic
Converter. The sensor output voltage varies in accordance with the
air/fuel ratio.
The sensor must be hot in order to operate normally. To keep
it hot, the sensor has a heater which is controlled by the ECM via a
duty cycle signal. When the exhaust gas temperature is lower than the
specified value, the heater warms the sensor tip.

Removal
1.
Turn the ignition switch OFF and disconnect the battery negative (-) cable.
2.
Remove the intake manifold.
(Refer to Engine Mechanical System - “Intake And Exhaust System”)
...
Specification
HO2S [Bank 1/Sensor 1] (Linear type)
ItemSpecificationHeater Resistance (x)2.4 ~ 4.0 [20°C(68°F)]
HO2S [Bank 1/Sensor 2] (Binary type)
A/F Ratio (x)Output Voltage(V)RICH0.6 ~ ...
Other information:
Hyundai Tucson (LM) 2010-2015 Owners Manual: USB Mode
✽ NOTICE - USING THE USB DEVICE
Connect the USB device after turning on the engine. The USB device may
become damaged if it is already connected when the ignition is turned on.The
USB device may not operate properly if the car ignition is turned on or off
with the USB device connected ...
Hyundai Tucson (LM) 2010-2015 Owners Manual: Owner maintenance
WARNING
Performing maintenance work on a vehicle can be dangerous. If you lack sufficient
knowledge and experience or the proper tools and equipment to do the work, have
it done by an authorized HYUNDAI dealer. ALWAYS follow these precautions for performing
maintenance work:
Park your veh ...