p0126 Thermostat and revs at idle

[jmonterr]

P0126 code it says insufficient coolant temp.
I replaced the thermostat and reset the engine light and it just comes back on

the car also revs itself its not to high probably from about 700 to 1200 but it does not happen constantly.

has anyone else had these types of symptoms any input would be helpful thanks

 

[mzdaspd3]

Here are other possible area's to look at




ECT sensor malfunction
Cooling system malfunction
Coolant thermostat malfunction
PCM malfunction