Reduced engine power light
 

Please help if possible. I have an 05 Lacrosse with 243000 on the clock. We bought it 3 years ago and found it was abused. After putting at least 5K into it (because my wife LOVED it) the latest issue is...
Randomly the car will just shut off! A message will come across the dash readout of reduced engine power. It looses all spark and I coast to the shoulder. After shutting off the key and counting to 30 it will crank and run. No check engine light on, however I have replaced wheel hub bearings and haven't gotten the abs and traction control lights turned off. This is highly irritating and unsafe. I've seen pcm, tps in other conversations. Advice??