There are two of them.
Only one.
4 cylinder Camry has 2 oxygen sensors.
The 5.2L has two oxygen sensors.
There is 2 oxygen sensors on the 2002 Nissen altima
It depends on number of cylinders the engine has. 4 cylinder engine has 2 oxygen sensors. V6 has at least 3.
there are 4 o2 sensors
2
The 2002 2.4L has 4. 2 on the exhaust manifolds, one before the catalytic converter and one after.
THERE ARE 2
Four
4 all together