I seem to pop this code if i idle the car for a short time (say 20 min). Its not that big of a deal really, it doesnt show up at all if i drive it. Just shows up after idling for a bit. I can shut it off with my scanner. What usually does this or shall i ask, what would be the most common thing that contributes to this???

 

I hate to speculate, but if it was my car I would start checking vacuum lines, clean the MAF, and check the EGR.. you most likely have a vacuum leak, probably a very small one.. How is the idle on the car? Does it get rougher when the code comes on while the car is idling? Eric

 

seems to idle fine even with the light on. runs fine too even though "restricted performance" shows up. I don't know though. maybe that's why im getting 27mpg...lol. ill start checking the vacumn hoses and work my way around I guess.weird thing is it only does it when I idle

 

Lol yeah it's funny that when you have a P0171 and your car is running lean you will see a huge increase in your mpg sometimes over %35.. I would say you have a gasket or a hose that's cracked and is setting off the code.. Try the easiest thing first though: clean the MAF and reset.. Then start checking for leaks.. Eric