GM 19178918 Sensor Asm,Heated Oxygen

The oxygen sensor is situated in the exhaust manifold for 4 cylinder models and in the left exhaust manifold for the V6 cars and it measures the oxygen content of the exhaust gas and provides a standard voltage output, which ranges between 0.1 volts in relationship to high oxygen or lean fuel mixture and 0.9 volts for low oxygen or rich mixture. The PCM utilizes this fluctuating voltage to manage the air/fuel mixture proportion in an effort to achieve an ideal of 14.7 ratio of air to one of fuel to reduce emission and optimize the function of catalytic converters. Engines with TBI, four-cylinder and V6, have an oxygen sensor while the V6 engines with CMFI and CSFI have three sensors. The sensor does not generate voltage below its normal working temperature of about 600-degrees F (360-degrees C), so during start up the PCM takes no input and hence runs in an open loop. If the engine gets to normal temperature, and the sensor gives a constant voltage of 0.35-0.55V, then a trouble code might be logged if, for instance TPS indicates that the engine is not idling . It is also possible for a sensor to take longer time in performing a function or for the voltage signals to be out of the usual range and this, in turn, causes trouble codes to be set because the PCM will then have to control the fuel delivery with the default settings it has rather than relying on the signals from the sensors. In order to function correctly a sensor requires good electrical connections, free flow of air, correct temperature and the ability to work with unleaded fuel. When servicing caution must be taken in such areas as; damaging the pigtails and connectors which are permanently attached, preventing contaminants from coming into contact with the electrical connector and sensor end, and positioning the silicone boot correctly. On some models there will be come a time to replace the said sensor, and at this time it may prove difficult to loosen if the engine is cold, in this case what needs to be done is to run the engine for several minutes. Transmission data Link sensor wiring should be disconnected from harness, the battery's negative terminal should be disconnected and vehicle raised and safely supported. The sensor should be delicately undone from the exhaust manifold and before doing this, a application of the anti-seize compound on the threads will be appropriate once the sensor is re-installed you will reconnect the electrical connector and then raise/lower the vehicle to reconnect the battery.

Various engine sensors and components have checking procedures,the engine coolant temperature (ECT) sensor is a thermistor that changes resistance with temperature, and a failure in the circuit can cause trouble codes. The resistance should be measured when cold and warm while ensuring reference voltage from PCM is around 5.0 volts for the verification. Manifold Absolute Pressure (MAP) Sensor monitors changes in intake manifold pressure then varies its voltage output accordingly. Look at the reference voltage and signal voltage with the ignition on and engine off, and observe voltage changes as the engine's vacuum changes. Intake Air Temperature (IAT) Sensor acts as a thermistor where you can measure its resistance at different temperatures to make sure it changes as expected. Also, use a scan tool to monitor the IAT sensor for performance. The oxygen sensor in exhaust detects oxygen content which you can check its millivolt signal while warming up your engine. Check whether the oxygen sensor heater has correct voltage or not. Vehicle Speed Sensor (VSS) provides speed data to PCM which can be checked for reference voltage. Depending on the type of engine, Camshaft Sensor and Crankshaft Sensor should be checked for resistance and proper signal output. Finally, Knock Sensors detect engine knock which should be checked for reference voltage and resistance. If any component fails these checks, replacement may be necessary.

Various engine sensors and components have checking procedures,the engine coolant temperature (ECT) sensor is a thermistor that changes resistance with temperature, and a failure in the circuit can cause trouble codes. The resistance should be measured when cold and warm while ensuring reference voltage from PCM is around 5.0 volts for the verification. Manifold Absolute Pressure (MAP) Sensor monitors changes in intake manifold pressure then varies its voltage output accordingly. Look at the reference voltage and signal voltage with the ignition on and engine off, and observe voltage changes as the engine's vacuum changes. Intake Air Temperature (IAT) Sensor acts as a thermistor where you can measure its resistance at different temperatures to make sure it changes as expected. Also, use a scan tool to monitor the IAT sensor for performance. The oxygen sensor in exhaust detects oxygen content which you can check its millivolt signal while warming up your engine. Check whether the oxygen sensor heater has correct voltage or not. Vehicle Speed Sensor (VSS) provides speed data to PCM which can be checked for reference voltage. Depending on the type of engine, Camshaft Sensor and Crankshaft Sensor should be checked for resistance and proper signal output. Finally, Knock Sensors detect engine knock which should be checked for reference voltage and resistance. If any component fails these checks, replacement may be necessary.

Oxygen sensors require an operating temperature of around 600°F. Below this temperature during warm-up, the ECM/PCM operates in open-loop mode and doesn't use the sensor's feedback. Heating elements in the sensors help reach operating temperature quickly.

The oxygen sensor needs good electrical connections, sufficient air circulation, the correct operating temperature, and should be used with unleaded fuel.

When replacing a post-converter sensor, ensure the vehicle is securely raised, disconnect the electrical connector, unscrew the sensor using the appropriate tool, apply anti-seize compound to the threads, and secure it while reattaching the electrical connector before lowering the vehicle.

The manifold absolute pressure (MAP) sensor monitors intake manifold pressure changes and varies its voltage output accordingly. To check it, you should check the reference voltage and signal voltage with the ignition on and engine off, and observe voltage changes as the engine's vacuum changes.

The intake air temperature (IAT) sensor acts as a thermistor. To check it, you can measure its resistance at different temperatures to ensure it changes as expected. Additionally, you should monitor the IAT sensor using a scan tool to verify its performance.

Yes. 19178918 are all the same for each position