On the bottom of the motor.
there are 3 in the front and 3 in the back of the motor near the fire wall
That is 31,000 ml
The best way to find out is go to your local auto parts store, ask for a haynes or chiltons manual on your vehicle. This will tell you everything you need to know about working on your vehicle.
Does it have a miss? check plugs and wires. Also a possibility of a bad throttle position sensor.
All O2 sensors are located on the exhaust system. Start at the exhaust manifold and work your way backward, and count them.
31L is 310 deciliters.
depends on the age and quality
I have a 92 lumina with a 3.1 and I found the crank sensor to be located on the passenger side of the engine in the back of the engine NOT on the side of the engine below the knock sensor. Hello, in my experience, all O2 sensors are located in the exhaust just after the manifold. It appears easy enough to change. If it is the crank position sensor you are looking for, take a look around the main pulley at the bottom of the engine, you may see a square-ish component located close to the actual pulley wheel, this would be the crank position sensor, it should have wires connected to it.