Changed Air Fuel Ratio Sensor In 2008 Honda Civic?

So we changed the O2/AFR sensor in our 2008 Honda Civic Sedan after having the car read and getting a p1172 (I think) code. On the reading it said "Faulty AF sensor" so we replaced it. The check engine light is still on but it runs smoother and gets better gas mileage than it ever has since we've had it! Code still shows up on the reader. Is it fine or should I look more into it? I got it up to 55 and 70 and it was running way smoother than it did before by a long shot. Should I worry with it? Can the check engine light be reset?

Added (1). Not a lot of exhaust either just the normal regular amount. It was LITERALLY just replaced 2 hours ago. (the AFR sensor) Does it take a while for it to click/register or what?

You can either reset the the light with a scan tool or just wait for the computer in the car to run the readiness test for that sensor and the light will go out on it's own.
Personally I would wait and let the computer decide when to turn the light off, it shouldn't take long, maybe a couple days at the most of combined driving. If you reset it with a scan tool you'll lose all the adaptive settings that the computer learns about your normal driving.

Could be the scan tool failing to clear the code. As long as the you don't have any other codes then try another scan tool. Make sure you do a live data scanmmonitor the new sensor

It will keep showing up until you remap the chip. It's expecting different values.

Have the code clears. Could also take a few longer drives to shut the light off. Monitor may need to see it pass twice before shutting it off.