I have had a problem lately with my car's steering. Once in a while, it seems like my car won't turn. The wheel is as hard to turn as if the car were off.  The SES light has recently come on intermittenly as well. I can use the paper clip method to get codes but it never has anything besides the 13 that everything is fine. The light doesn't stay on all of the time. It will come on after about 5 minutes of driving or more. My understanding of this feature is that once a code is trapped, it will show it until the codes are cleared.  Could there be some corrilation between the two problems?  My car also has taken up the bad habbit of turning itself off if I am traveling above 40 and attempt to stop quickly. Obviously, power steering, brakes, big problems.... Anybody have any ideas as to a possible cause?

PS problem can be that pump needs replaced, but code 13 is the O2 sensor.  12 is the system check code.

"Oxygen sensor voltage stays between 0.35 and 0.55 volts for 60 seconds when the TPS signal was above 4%. The engine had been running for at least 2 minutes."

http://www.troublecodes.net/GM/

I had problems of electrical shutdown that was due to corroded battery cables.  Cleaned them and they worked fine!  You may have a bad electrical connection elsewhere also.