My 2001 impreza outback died while driving and won't start

What is your question?

My car was sputtering for a brief moment yesterday but corrected itself I figured it was just time for a tune up but today while driving and it died. There wasn't any loud noises or knocking so I don't think it was a piston. I had a buddy tow it to my house and imeadiatly checked the fuel lines to see if the gas was running through and it was fine. I pulled the spark plug wires out and found oil in the spark plug wells. I figured I just needed to replace the valve cover gaskets I cleaned out the oil and found that it still won't start. The outback cranks but just won't start. Any ideas on what it could be?

How long has your 2001 Subaru Impreza had this problem?

A couple days