Sometimes it drives fine and sometimes the engine will start stalling?

I would try to get the codes
and post them for more help
also check /replace ASD relay
check /replace crank sensor

I would go for the crank sensor and replace
the code you gave are you sure of it
do u have P 0000 code
let me know

You will not lose the steering when the engine stalls. You will just lose the power assist and you'll need both hands to turn the steering wheel. If you aren't familiar with that, try coasting through an empty parking after turning the engine off so you know what to do in an emergency like you just had.

When the Engine Computer detects a problem, it sets a diagnostic fault code. It will also turn on the Check Engine light if that problem could have an adverse affect on emissions. In the case of using more fuel, that increases emissions. Besides the increased fuel consumption, there's another problem with waiting to have it repaired. There is always a long list of conditions that must be met to set a fault code. One of those conditions is that certain other codes are not already set. The computer constantly compares numerous things to each other to figure out when something is wrong. If it sees a problem with a circuit, it knows it can't use that as a reference for other circuits so those other circuits may not get tested while you're driving. When you finally get the first problem fixed, the computer can resume all of its self-tests. That's when a code for a totally new problem could show up and the Check Engine light will turn on again. You just paid to have a problem solved and the light is still on. What you don't realize is this is a new problem that your mechanic had no way of knowing about earlier.

The next thing to be aware of is fault codes never say to replace parts, in this case, one of the oxygen sensors. They only indicate the circuit or system that needs further diagnosis. You didn't list the engine size or mileage so I can't tell you how many different oxygen sensors you have but it will be at least two. If the mileage is relatively low it is much more likely there is a wiring problem related to one of the sensors than a bad sensor. Only diagnosing the circuit will tell for sure. About 50 percent of the time replacing the sensor will not solve the problem.