(Portland, OR)  --  A man is facing charges after allegedly stabbing a woman inside his car in Northwest Portland.  Police say an officer was in the area on a separate call when he heard the woman screaming for help.  He called for backup and pulled the car over, prompting the woman to exit the vehicle and tell officer's she'd been stabbed.  The driver exited the vehicle and surrendered without incident.  Police say the two were arguing when the stabbing occurred.