Attaching sensors

This is my first post I'm sure I'll do something wrong, but I have a question.

Can I attach a car's O2 sensor to arduino and fluctuate a hydrogen fuel cells output with the readings?
Of course I'll make a preset scale to what the output should be and all.

Welcome on the forum,

Technically it might be possible, depends on the interfaces of the sensor and fuel cell.
We need a lot more information about the hardware to give a meaningful advise.

Can you post (links to) the datasheets/specification?

That said, safety warning!
Besides if it is possible there is always a risk working with H2 as it can implode/explode.

Well I would use a dry cell such as this

And I would like to vary the ouput to the fuel cell by an integer of the O2 sensor.
Such as this:

So that at say 24 volt 9amps the cell is gnerating 2 liters of hho per minute, I could have it turned down if there wasn't enough oxygen being passed through the engine (say at idle)