sounds like your engine thermostat is sticking open
P0125 means "insufficient coolant temperature for closed loop fuel control" Insufficient Coolant Temperature for Closed Loop Fuel Control Read more at: http://www.obd-codes.com/trouble_codes/ Copyright © OBD-Codes.com
External Air temperature control, the unit in the dash where you control the AC and Heater
P0125: insufficient coolant temperature for closed loop fuel control you need an ECT sensor engine coolant temperature
The exhaust gas recirculation system (EGR) is an emissions control system that recirculates some of the exhaust gas back into the intake in order to re-burn any excess fuel vapor that leaves the engine. It is basically operated by a valve to control circulation. "Valve lift insufficient" means that the valve is not opening enough to circulate exhaust gas as much as the engines computer deems necessary. The vehicle will not pass an emissions test in this condition.
It depends on the make, but most likely a malfunction of the egr temperature sensor.
Trouble code P0125 means: Insufficient coolant temperature for closed loop fuel control
Check temperature control cable for binding.
You're going to have to be more specific with your question. There are many components to the emissions control system.
There is no such thing on this car.
Answering "What emissions control device on a car lowers carbon monoxide content?"
no the fuel pump it self does not control emissions
what does a insufficient coolant temperature for closed loop fuel control mean and what can i do to fixs it on a mercury mountaineer 1997 engine is a 5.0