2010 Silverado rough cold start

[FastLane]

My truck has a hard time starting when it's cold. I believe once the O2 sensors kick in the cpu then adjusts everything and it runs great. Any ideas? I'm guessing an intake leak. I put new plugs and wires in it and it made no difference.

 

[The_Eric]

Is it a flex fuel truck? Sometimes the learned alcohol content is off (if it doesn't have a sensor) and can cause the rich codes you have. If that's the case, you'll have to go to a shop with either factory scan tool or a capable aftermarket scan tool to reset the alcohol content.

Look through the data pids for the learned alcohol value and see if it matches what you put in the tank. If not, its wise to verify actual content in the fuel before resetting anything.

 

[GMguy84]

error

 

[FastLane]

You were right. The truck thinks the fuel is 60.4% alcohol when it's only 10%.