engine stalls, and then dies while driving...fuel pump, or fuel filter?

My guess is a clogged fuel filter and possibly a worn out fuel pump from your story. Replace the fuel filter if it's not been replaced in recent memory. A plugged filter will ruin a fuel pump eventually. Fuel filters are most often neglected until they damage the pump. After that, check the fuel pressure while driving with an external test gauge hooked up. That will tell you what you need to know about the fuel system. Use adequate precautions and procedure while checking pressure, there's fire danger and you should have goggles on and fire protection handy. If you want to find a Toyota specialist, here's a directory link: http://repairpal.com/toyota-repair-in-snohomish-washington

Let the car sit for a few hours or over night....the fuel filter is changed every 30,000 miles so if its been in a while do as i recommend....after sitting remove the gas cap, remove the fuel pump fuse, if you cant find it...jack the car up on the gas cap side in the rear and remove that rear wheel, be sure you have the keys in your pocket...donot turn on the ignition until you are completely finished....slide under the car and look for a module looking metallic sort of rounded shape object with rubber lines and possibly even steel lines going to it shouldn't be big part, as a matter of fact buy the new filter for your car and use that as a template to locate and disconnect the old filter, may be under pressure so wear safety goggles, make certain you have a rather large drain pan to catch the running gas, be sure you follow the correct installation as per manufacturers directions(arrow should represent the fuel flowing from the fuel tank, pointing forward toward the direction of the front of the car. After you replace it correctly secure the clamps start it up first reinstall the fuel pump fuse and the gas cap, observe for any possible fuel leaks and correct as neccessary, bang the old filter out on a clean white rag and see if any dirty debris comes out of the openings, if so you may have fixed the problem, if it is dirty and the car runs slightly better, you may have to flush the fuel tank, fuel lines and fuel injectors for fear of possibly contracting a bad load of dirty/watered fuel at some gas station, first rty fuel additives syuch as fuel injector cleaner, dry gas and a full tank of high test and see if that helps, also mremember especially in the winter, keep your fuel tank no lower then 1/4 empty, anything lower then this invites any contaminates that may be lurking at the bottom of your fuel tank..thus entering the lines and clogging the works again!!Good luck hope this info helps!!!