map sensor or something else?

[totta Crolla]

Ok the cold start.
When you crank the engine you are also injecting some extra fuel from a separate cold start injector hence the initial jump in revs. once this extra fuel is burnt (to help start the engine) the main injectors take over.
Expect to see some instability in the idle until the engine is warm.
(just like your video tbh)

After reading your first post again and assuming the car was ok before the work was undertaken I would say that there is air in the cooling system and
this is causing a problem with the water temperature sensor.

Also you have a modified exhaust ?
Modified inlet ?
To get more air in and out of the engine ?
You have no Oxygen sensor, correct ?
The popping sound is probably because the engine is running lean at idle.
This can be corrected however.

Are you getting error codes from the ecu ?