2011 Silverado 1500 5.3l rough start

[Scotskra]

My 2011 5.3l Silverado with 58000 mi. has codes po172 and po175. It runs rough on cold starts and sometimes feels like a miss waiting at stoplights. I have tried cleaning mass airflow sensor. Today I changed spark plugs and have ordered new mass airflow sensor. Still runs rough. Any ideas? Thanks 

[sefiroxx]

Mass Airflow Sensor (MAF)

Defective Manifold Absolute Pressure Sensor (MAP)

Engine mechanical problems

Defective Oxygen Sensor

Defective Fuel Pressure Regulator

Defective Coolant and/or Air Temperature Sensor

Thermostat is stuck open

Ignition Misfires

Defective Throttle Position Sensor

Defective or restricted fuel return line

Defective Fuel Injectors

[Scotskra]

Sefiroxx. How do I narrow it down from all these possible issues?  I got the new mass airflow sensor today and will install tonight. 

[sefiroxx]

You'll need a one scanner with an ability to read data streams as well as other tools: some failed/failing items will throw a code, others will just provide bad data.

Mass Airflow Sensor (MAF)
- scanner to confirm amount of flow

Defective Manifold Absolute Pressure Sensor (MAP)
- scanner to confirm proper atmospheric pressure

Engine mechanical problems
- tool to check compression

Defective Oxygen Sensor
- scanner to confirm voltage signal and STFT

Defective Fuel Pressure Regulator
- fuel pressure test guage

Defective Coolant and/or Air Temperature Sensor
- scanner

Thermostat is stuck open
- engines does not get warm enough

Ignition Misfires
- code set

Defective Throttle Position Sensor
- scanner to show tps angle and that it moves smoothly

Defective or restricted fuel return line

Defective Fuel Injectors
- usually misfire code or excessive LTFT numbers

[Scotskra]

Thanks for all the broad ideas. I searched a little further and found a video 

about these flex fuel motors resetting with wrong alcohol content settings. I brought it to my mechanic he said it was running as if there was 58% ethanol in my fuel. I don’t know where you gas up but my 87 contains no more than 10% ethanol. It was literally a 2 minute fix. Wasted my money changing the mass airflow, the spark plugs I’ll chalk up to preventative maintenance. I hope this helps someone searching with the same issues.  After resetting my truck runs and starts like it always has.