Service Engine Soon Light?

It could be a bad fuel injector for that cylinder, or coolant leaking into that cylinder, or low compression on that cylinder.

This guide will tell us for sure by getting the codes

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down this guide and report back.

Have the trouble codes checked. Let us know.
How long since a tune-up? Check the tps.

You may need to clean throttle-body and idle air control.

Remove the throttle-body to clean. Some of the national brand autostores used to check trouble codes for free. There should be some codes.

In the picture, #2 should be the iac.

Let us know.

Any codes?

I'd use a scanner and look at idle and idle required. Idle required is what the computer is trying to get it to idle at. Idle is the actual idle. If idle required is higher than actual idle, the computer is having problems, for some reason, trying to raise the idle. I'm not saying the computer is faulty, there may be a problem with input to the computer from different sensors. Without something to point us in the right direction, it is hunt and peck.

You may be loosing anti freeze into engine. If your exhaust is smokey and smells like anti-freeze you probably have a bad head gasket. The low coolant level and/or coolant loss can create air bubbles in the sytem that need to be burped or after you did the water pump you have to burp the system. You do this by turning the heat all the way hot and fill the system till top. Then start car and wait unitl it reaches operating temperature and topp off again. Put the radiator cap on and drive around some. When the car cools off check the fluid level, if it has not changed, there is probably not any air. Also see if coolant is, "Foamy" as that is indication of air in sytem. The heater might have had to burp out a bubble before fluid could flow into it. As long s it does not do this everytime it is okay. But, if you are loosing coolant and cannot find a leak it may be a bad head gasket. You can do a compression test or coolant sytem pressure test to check this.

Sounds like the idle air control valve not maintaining the idle speed.

The dealer is aware that there's a problem within the engine management system why couldn't they fix it before selling it to you? If it was me I will say goodbye and never comeback.

If you really want this vehicle get it scanned for code/s this will tell you what's causing the CEL to come on and go from there

CIRCUIT DESCRIPTION
The Intake Air Temperature (IAT) sensor is a thermistor which measures the temperature of the air entering the engine. The Powertrain Control Module (PCM) applies 5 volts through a pull-up resistor. When the intake air is cold, the sensor resistance is high, and the PCM will monitor a high signal voltage on the IAT sensor signal circuit. As the intake air warm, the sensor resistance becomes lower, causing the PCM to monitor a lower voltage. If the PCM detects an excessively high IAT sensor signal voltage, a low temperature is indicated, and DTC P0113 will set.

CONDITIONS FOR RUNNING THE DTC

†DTCs P0101, P0102, P0103, P0117, P0118, P0125, P0128, P0502, P0503, P1114, or P1115 are not set.
†The vehicle speed is less than 56 km/h (35 mph).
†The mass air flow is less than 12 g/s.
†The engine coolant temperature is more than 60°C (140°F).
†The engine run time is more than 3 minutes.
CONDITIONS FOR SETTING THE DTC

†The IAT signal voltage indicates an intake air temperature that is less than -37°C (-35°F).
†The above conditions are present for at least 20 seconds.
ACTION TAKEN WHEN THE DTC SETS

†The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
†The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC

†The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
†A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
†A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
†Use a scan tool in order to clear the MIL and the DTC.