P0171 code 2017 colorado v6

[ricky c.]

Check engine light is on and I get service stability track randomly. My gas mileage is pretty bad average 13 miles pg. Cleaned MAF, changed spark plugs, don't see any vacuum leaks, cleaned the 4 VVT solenoids. Any ideas on what to check next 

[CamGTP]

Just a visual of no vacuum leaks or you've smoke tested the engine for vacuum leaks?

 

If a smoke test shows zero leaks then it could be an injector issue or even the o2 sensor that is at fault. Hard to say for certain right now.

[ricky c.]

I did a smoke test and couldn't see any leaks. Also the onstar service sends me an email alert that there is an issue with my emissions system

[madcratebuilder]

What are the short term and long term fuel trims?  Random ST can be harness or abs wire.