Engine wont start

Engine Performance problem 6 cyl Four Wheel Drive Automatic 100K miles

I had taken the vehicle into a shop to check why it wouldn't start. It turns over, starter, battery, everything sounds fine, just simply doesn't start. The mechanic advised I needed a fuel pump. I just changed the fuel pump and the results are no different. It cranks, but won't fire /start up. What should I check next (limited funds).

I can check voltage, but I had just replaced the battery about 2 months earlier. The issue started when I was driving. The vehicle simply just shut off (I only knew as I lost power steering, brakes and the dash lights came on), there was no unusual noises, nothing. Just cut off, I coasted to the curb. Historically I have had issues w/ the headlights dimming when I do many things, turn a blinker on, turn the heat/ac on, hit the brakes, everything I did would dim the lights (that had been happening for quits some time, but never impacted its ability to start or run (always ran fine), this came up all of a sudden. Should I start w/ some cheaper electrical parts? It really sounds like it should start, just doesn't.

The check engine light had been on and off. I had a friend test the code w/ a hand held. It stated that there "were no errors".

Thanks.