check engine light came on
 

I have a 2014 Silverado 1500 LT 5.3 Liter engine. I had an engine light on and stopped by the auto parts store and they checked the code and said it was my mass air flow sensor. (I didn't think to ask them what the code was). But I looked online and found out that you can test it by unplugging the sensor and the engine should die if it was good. I tried that and it kept running and the fans turned on??? so I thought it was bad. I replaced it and tested it and the engine still runs and the fans turn on. any help??

Is the malfunction light still on?
Run a diagnostic scan again and post the trouble code.

no the light went off before I changed it. I'll run it by the auto parts store and have them put the obd on it and see what it says.
thanks

I went by the auto parts store and they came up with 3 codes,
P0172 fuel trim system rich
P0175 fuel trim system rich bank 2
P050D cold start rough idle
I looked it up in my Haynes manual and it says the same thing. but that doesn't tell me anything. the guy at the auto parts store said it could be my fuel
injectors and to run some injector cleaner through it at see what it does. that's what I'm doing now. more to come later

Is it a Flex Fuel engine?

yes it is

check the fuel alcohol composition value with a good diagnostic tool. It's a buggy system that tends to go out of whack. If the value is some nonsense (like 70%) then reset it.

I have to do this constantly on mine.

ok thanks