I've got a 2008 Mazda 3 that runs great most of the time. I had an issue where my car, running 60 mph, bogged out. The rpm's dropped, battery light flashed on (maybe the check engine light also) but only for a second, everything caught and car drove like it should. I thought it may have been my cruise control so I cut it off and was maintaining speed around 60 and it did it twice more.

I pulled my car over, turned it off, popped the hood and checked to make sure i had a good terminal connection on my battery. Tight and clean (hold the jokes). Car started back up just fine and I was able to get my car to the mazda dealership with no more issues. They told me it sounded electrical and, after doing a reading and seeing low output, decided it was the alternator that needed replacing.

Dropped $600, thought i was good but it happened again. Took it back to mazda, couldnt reproduce the problem. Month went by and yesterday it happened like 7-8 times in two miles. Pulled over, got it towed, thought it was a fuel pump but mechanic (different mechanic this time) couldn't reproduce issue, checked fuel pump and saw no other options with no check engine light on to produce a code.

I had replaced spark plugs several months before, the car has a new battery and has always been serviced regularly.

Mechanics are at a loss. Any suggestions?