P0171 popped on while driving from Tempe to Sedona. Luckily I was only 25 mi away when the Engine lost power and began sputtering out the exhaust. Was climbing some pretty serious mountains and I always do have problems with that, I'm usually behind the semis with the hazard lights on. I made it to town and went straight to the auto parts store. I bought MAF sensor cleaner MAF assembly cleaner and new spark plugs. The weird thing is on the way to the hotel from the auto parts store the light went out...and the truck started running okay again.... This morning I'm still going to clean the air filter clean the MAF sensor and assembly and spray out the air filter and let it dry, and change the spark plugs. Yes I have all done before of course but it's been a while. One thing I have never done is change the O2 sensors. I don't know why the light would come on and then go out. Any advice appreciated I'll keep you updated on what happens
Of course this couldn't happen back in town when I'm home with my garage and all of my tools lol....

Thanks in advance,
Backporch
2007 Hummer h3 I-5
147k miles
Air doc air intake

 

Only code in history?
air:fuel ratio not at 14.7:1
Causes:
The MAF (Mass Air Flow) sensor is dirty, Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled.
There could be a vacuum leak downstream of the MAF sensor
Possible cracked vacuum or PCV line/connection
Sticking/plugged or failed fuel injector
Low fuel pressure
Exhaust leak between engine and oxygen sensor
Possible Solutions:
Clean the MAF sensor.
Inspect all vacuum and PCV hoses, replace/repair as required
Inspect all hoses and connections in the air intake system
Inspect and/or test the intake manifold gaskets for leakage
Check for proper fuel pressure

 

Thanks for the help! I cleaned MAF sensor and MAF assembly, air filter and replaced spark plugs with AC Delco iridium. Seems to be ok now! Hope it lasts lol

 

Curious of the old spark plugs condition. Post a picture.

 

They all look pretty much like this

 

They all look pretty much like this