Check Engine light

[Brakeman]

I have a 99 Toyota 4 runner 3.4 automtic. I continue to get a code PO171 Lean engine. Any ideas.

 

[MGP]

Instead of me explaining it, this does a much better job than I could:

3rd Gen. 4Runner OBDII Code P0171 and P0172

 

[DavidAlexander]

Instead of me explaining it, this does a much better job than I could:

3rd Gen. 4Runner OBDII Code P0171 and P0172

2nd that. Clean your MAF or check your o2 sensors

 

[bbt1414]

So I had this same problem, and I ended up cleaning the MAF sensor and still didn"t work. In the end replaced it with a rebuilt one from the auto parts store and no more check engine light.