Q: The eml light turned on and then the car decelerated. Just wanted to know what it means and if I require a mechanic

EML refers to the electronic throttle control system. It’s a system integrated into the engine and body controllers to select the proper the throttle position for whatever the driver is demanding. There are several sensors and actuators in play and the light comes on if a fault is detected in any of those components The components like accelerator position sensors and throttle position sensors are redundant, so you are probably not in immediate danger of being stranded, but you should have it checked out at the first opportunity. A technician can plug into the diagnostic connector and read the codes stored in the system to determine what steps need to be taken. If you contact Your Mechanic, you can have a technician come to your home or office to read the codes in your car and let you know what needs to be done.