My 2001 Hyundai Sonata has a recurring problem. Everytime at 20 mph (when the car is slowing down on its own), I feel a slight pressure on the engine that slows the car down even further. This does not feel natural to the car and started a few months ago. I took the car to Hyundai service and no trouble codes were found. They acknowledged that the problem exists but they didn't know what it was, and they sent me on my way. Any ideas what this may be?
Thank you, Matt