No CEL so far 400 miles later, plus it's running smooth and I'm able to hold a cruising speed which was the original problem.

Well in the event that you're short on cash and would really not want to be spending money on sensors you don't actually need, you could've disconnected the o2 sensors and see if the car performed differently. When the O2 sensor is absent, it's running in open loop mode (warm up mode) so the car should behave differently then the way it was before you disconnected them.