What is the emissions system problem on the honda civic 2019?

If You see that there is an emissions system problem light on the dash in Your 2019 Honda Civic that means that there has been a problem detected by one of the emissions sensors. These are in place after the catalytic converter and help measure the exhaust gas to make sure that it has been properly cleaned by the cat. In general this will cause Your vehicle to fail an emissions test if You need to run it through one in Your state. It can also be a sign of a broken or damaged emissions control system or catalytic converter on Your car. I recommend letting a mechanic take a look at the vehicle to see if there are any components that have failed. It could also just be a sign of a failed sensor.