Question about the Thermostat Light

So I’ve been having some issues with my 2013. In August, the EGR valve said it was clogged so i had it cleaned. The light came back on at the end of December and i had it cleaned again because i don’t want a car payment. It came back on two weeks later and he said the intake manifold was also dirty so he took that apart and cleaned it and replaced the seal. During this whole time, it never ran rough or anything, it was just throwing the emission codes. Today i was driving and the thermostat light flashed red for about five seconds maybe and then turned off. I pulled over and waited a bit and it didn’t come back on when i started it. I read online that maybe it can be from air bubbles getting trapped when the intake is cleaned. Is there any truth to this? Do you think it’s drivable? Or do i need to take it back to the mechanic? I really, really, really do not want a car payment but i also don’t want to keep investing too much. I replaced the engine like three years ago and the water pump at the same time. Is it worth it to keep paying more?