There's 2 of them on that engine. Sorry to be the 1 to tell you but they are underneith the intake manifold. You must remove the intake to even see them.
they are located under intake manifold The #1 sensor is located in the front of the engine and the #2 sensor is located in the back of the engine. Remember to replace the intake gaskets once you replace the sensor/s. The total time it took me to pull the intake and locate the bad sensor was about 6 hours. Hope this helps
The 2002 GMC Sierra: temperature sensor is located on the front of the engine. The sensor will be just above the thermostat housing.
On engine block
It is located on the tailshaft of the transmission, on the passenger side.
near the oilpan, on the side of the motor, towards the bottom.
Sensor 2 is the downstream sensor (after the catalytic converter). Bank 1 is the drivers side of the engine
The knock sensor is on the starter side of the engine. It is abut half way between front and back.
the knock sensors are located in the top of the engine block. The intake has to be removed to get to the sensors.
Bank 2 sensor 1 would be the first sensor located on the passenger side exhaust pipe closest to the engine.
On a 2004 GMC Sierra with a 5.3 engine, the knock sensor is locatede under the intake manifold. You have to remove the intake to get to them. There is 2 of them, so it might be better to change them both while it is apart.
It is on the engine fire wall just under the passenger side windshield wiper.
The B1 S2 is located in the exhaust system from the drivers side of engine after the catalytic converter.