No Fire To Plugs

My daughters 98 Eclipse GS with 2.0 has died. She was driving along and the engine died. She restarted it and it ran fine. The next time she tried to start it, it didn't want to start but finally did and ran rough. Then it died completely and will not start again. There is no spark to the plugs. I have scanned it and it has no fault codes. I have replaced the coil pack. Advance Auto suggested replacing the crank positioning sensor. Can I test this sensor before I spend $80 more ? Any other ideas ?