Honda Fit: Surging and hesitating while driving at highway speeds:

This customer brought her vehicle that was surging and hesitating while driving at freeway speeds. The check engine (service engine soon) light was not on and never illuminated for the customer. We road tested and verified the concern. We used the scan tool to check for codes, no codes were present. We then road tested and looked at the cylinder misfire data, we noticed when we experienced the surging the engine was misfiring on cylinder #1. When we removed the spark plugs and inspected them we found worn spark plugs. We then tested the ignition coil and found that the coil had weak spark output. We replaced all spark plugs and the cylinder #1 ignition coil. After the repair we road tested the vehicle and the hesitation and surging were no longer present.