You can. Using the G6
Just need to keep the sensor number handy. Remove the transmitter and wait 10 minutes.
Start like it’s new. Reinstall transmitter and wait your 2 hour warmup. 🤷‍♂️

Thanks everyone! I wanted to ask this and see how true it was at actually doing this! I had seen little tricks on Facebook on tricking your Dexcom G6 transmitter by taking it off the sensor, making the sensor think that you have taken off the transmitter, and not take the sensor off of your skin (site)...just like changing it but not actually taking off the sensor and then restarting it....just like starting a new sensor. I wouldn't think the numbers you would get could be very accurate.

It’s simple…. I do it when there’s an issue( hold up) getting new sensors!

Thank G-d I never needed to on regular basis but I did try as some say second 10 days were more accurate than first. Found this wasn't true on G6 but everyone different. DM if want further info

I’ve extended my guardian 4. It ends in 7 days and I’ve gotten 6 more by just taking it off when it ends and just recharging the transmitter and plugging it in as new. It works.