Rpm jumps at start up, vehicle seems to be hunting at freeway speed, have replaced mass air flow sensor, but not throttle body position sensor. could it be the ignition coil?

DTC P0121: Throttle Position (TP) Sensor 1 Performance
Circuit/System Description
The engine control module (ECM) uses the following information to calculate an expected airflow rate:
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The throttle position (TP)

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The barometric pressure (BARO)

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The manifold absolute pressure (MAP)

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The intake air temperature (IAT)

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The engine RPM

P0121 The predicted air flow and the predicted MAP combined are outside a calibrated range for more than 3 seconds.
Circuit/System Testing

1. Inspect for the following conditions:
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Vacuum hoses for splits, kinks, and proper connections as shown on Vehicle Emission Control Information label



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Inspect thoroughly for any type of leak or restriction



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Air leaks at throttle body mounting area and intake manifold sealing surfaces



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Throttle body for dirt, debris, and coking--Refer to Throttle Body Cleaning.


2. Allow the engine to reach operating temperature. Observe the MAP Sensor Voltage parameter with a scan tool. Voltage should be more than 0.8 volt and less than 4 volts.
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If more than 4 volts or less than 0.8 volt, refer to DTC P0106.

3. Idle the engine. Observe the MAP Sensor kPa parameter with a scan tool. Increase the engine speed slowly and then back to idle. The MAP sensor kPa should change smoothly and gradually as engine speed is increased and returned to idle.
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If the MAP sensor kPa does not change, refer to DTC P0106.

4. Take a snapshot of the engine data list while performing the actions listed below. The mass air flow (MAF) sensor g/s should change smoothly and gradually as the engine speed is increased and is returned to idle.
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Idle the engine.



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Increase the engine speed slowly to 3,000 RPM, then back to idle.



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Exit from the snapshot and review the data.



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Observe the Mass Air Flow (MAF) Sensor parameter frame by frame with a scan tool. The MAF sensor g/s should change smoothly and gradually as the engine speed is increased and is returned to idle.



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If the MAF sensor g/s does not change smoothly and gradually as the engine speed is increased and is returned to idle, refer to DTC P0101 or P1101.


5. Inspect the throttle body for the following conditions:

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Loose or damaged throttle blade

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Broken throttle shaft

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Any throttle body damage

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If any of these conditions exist, replace the throttle body assembly.

Could be a few things. But here are the obvious. Check for a vacuum leak around the intake. When you put the car into drive it starts putting strain on the engine, a vacuum leak will give it too much oxygen and cause a fuel mixture issue / reading.
If nothing wrong there, you may have a bad throttle position sensor. When you put the car into drive and it starts putting strain on the engine it will pull the idle down then the sensor will adjust it automatically. Hope this helps.

P2106 - Throttle Actuator Control System - Forced Limited Power

Engine power and RPM's will be limited and cruise control will be disabled due to a throttle fault. This occurs when one or more throttle positions sensor readings are out of range or do not agree with each other. Sometimes this code is also set if the throttle plate cannot return to the idle position due to carbon buildup in the throttle body (you might try cleaning it). The code can also be caused by a bad mass air flow, output shaft speed, turbine speed sensor, or crank position sensor. If the throttle body is clean, operates smoothly, and no other sensors are failed, then you might have to just replace the throttle body.

P0068-MAMFQLD PRESSURE/THROTTLE POSITION CORRELATION
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Theory of Operation
This DTC sets when an unexpected high intake manifold air flow condition exists that
can lead to increased engine speed and puts the NGC into a High Air flow Protection
limiting mode. The High Air flow Protection feature includes RPM limits for when a
Throttle and or MAP sensor limp-in fault is present.
When Monitored
During all drive modes.
Set Condition
If vacuum drops below 1.5Hg with engine RPM greater than 2000 RPM and closed
throttle. One Trip Fault. Three good trips to turn off the MIL.
Possible Causes
-VACUUM LEAK
-RESISTANCE IN THE (FS56) 5-VOLT SUPPLY CIRCUIT
-(FS56) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
-RESISTANCE IN THE (Kl) MAP SIGNAL CIRCUIT
-(Kl) MAP SIGNAL CIRCUIT SHORTED TO GROUND
-RESISTANCE IN THE (FS55) 5-VOLT SUPPLY CIRCUIT
-(FS55) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
-RESISTANCE IN THE (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT
-(K22) TP SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO GROUND
-RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT
-MAP SENSOR
-THROTTLE POSITION SENSOR
-PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
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Sir, your question is not very clear, but I will still try to post a solution here. Engine missing could be due to any problem in fuel system, ignition system, engine or ECM as well.

LOW ENGINE IDLE SPEED (Poor idling):
-Throttle body (do the cleaning and idle speed learning)
-A /C signal circuit
-Fuel pump control circuit
-Fuel pump
-Intake system
-P C V valve (clogged or open) and hose

ROUGH IDLING:
-Cylinder Compression
-Ignition system (Igniters, spark plugs, wiring harness)
-Spark plug fouled, gap too wide or too short. (1.00-1.1 mm)
-Fuel injector circuit
-E C M power source circuit
-Fuel pump control circuit
-Fuel pump (required pressure 44 psi - 49 psi)
-Throttle body (cleaning)
-Intake system
-P C V valve and hose
-Air fuel ratio sensor
-Heated oxygen s ens or
-Mass air flow meter
-Idle hunting
-Throttle body
-Intake system
-P C V valve and hose
-Air fuel ratio sensor
-Mass air flow meter

HESITATION/ POOR ACCELERATION:
-Fuel pump control circuit
-Fuel pump
-Spark plug
-Ignition system
-Fuel injector circuit
-E C M power source circuit
-Mass air flow meter
-Throttle body (do cleaning)
-Intake system
-Valve timing
-Cylinder Compression

P0068 Symptoms - Engine Light ON (or Service Engine Soon Warning Light)
- Lack/Loss of power
- Engine rough idle Possible causes - Large vacuum leak
- Leaking air duct system
- Mass Air Flow (MAF) poor electrcial connection
- Manifold Absolute Pressure (MAP) poor electrcial connection
- Faulty Mass Air Flow (MAF) sensor
- Faulty Manifold Absolute Pressure (MAP) sensor
- TP sensor not seated properly.
- Faulty Throttle Position (TP) sensor.
- Dirty throttle body
When is the code detected? The Powertrain Control Module (PCM) monitors operation rationality check by comparing sensed throttle position to mass air flow readings
P0068 DODGE Description The Powertrain Control Module (PCM) monitors a vehicle operation rationality check by comparing Throttle Position (TP) to Mass Air Flow (MAF) readings. If, during a self-test, the comparison of the TP sensor and MAF sensor readings are not consistent with the calibrated load values, the test fails and a diagnostic trouble code is stored in continuous memory.

If it only happens in one particular speed/RPM then I would be looking into TPS throttle position sensor. Please check and spray carb cleaner on the MAF mass air flow sensor only.

First ensure that the throttle interior is really clean, a surface layer of grime can upset the ECU's ability to meter and govern the air entering the engine. If the throttle body interior is found to be really oily and dirty check on the idle air control valve and make sure that it too is cleaned up. Next put the ignition switch in position 2 (on, but no start) and depress the accelerator fully and release. If there is an issue with the throttle position sensor this procedure can help the ECU relocate the throttle plate position. Start the engine and if it is still hunting locate the air mass meter (AMM) on the air ducting immediately next to the air filter and disconnect the electrical connection. Does this remove the hunting aspect?... the rev speed might change but for the moment concentrate on the evenness of the tick-over. If the idle is even when the AMM is disconnected but hunts when connected then look at replacing your AMM. Try spraying the AMM with no residue electrical cleaning spray to see if this improves matters.

Check the Idle accelerator valve located on front side of throttle body, it is either stuck or needs cleaning real bad, this is what controls your idle speed, by letting small amount of air in. It has a plunger on it that moves back and forth slowly to adjust amount of air mixture, it is controlled by computer. Unplug it and just turn on key and check for voltage.This valve gets real gummed up, probably need to take apart throttle body and clean. HUNT

It is what you call hunting. Carb or throttle body injection?. more than likely TBI. Could be the throttle position sensor,The mass air flow sensor, fuel pressure regulator. have the fuel pressure ck'd first.. then the throttle position sensor. then the maf sensor. Have the maf sensor cleaned, They are very expensive. Make sure the air cleaner is clean, clean. it and the maf work together. - good luck, Ned