2006 Silverado is running lean.

[ted-c]

My 2006 Silverado gets codes p171 and p174. I bought this truck new and it only has 11,000 miles on it. It's a 5.3 flex fuel motor and I've allways run it on E-85 and it runs good, just has the check engine light on all the time. It started this about a week ago. Any ideas on why I'm getting these codes??

[Meccboy]

There are several PCM programming updates for lean codes and for E-85 re-calibrating. This must be done with the dealer scanner and computer terminal.
Also may have intake manifold gaskets leaking vacuum, or lean running injectors-which can be cleaned.

[ted-c]

Thank you for that info, now I have a starting point. Although, I'm really disappointed that I'm having trouble with this truck with only 11,000 miles on it. I had a '99, '02, and '04 that all went over 120,000 miles with no repairs. They all had the 5.3 but ran on gas only.

[ted-c]

Well Meccboy, I owe ya one. I dumped a can of fuel injector cleaner in it and filled it up. By the time I used half of that tank, the lean codes cleared. The light has not come on since. Thanx!

[butchkaz]

Well Meccboy, I owe ya one. I dumped a can of fuel injector cleaner in it and filled it up. By the time I used half of that tank, the lean codes cleared. The light has not come on since. Thanx!

Thanks for another one MeccBoy ! Good job.