P0171 code

[OverlanderKing11]

A few days ago i got the surprise of my life, a toyota with a problem and its a p0171 code. I know its something with the air and fuel mixture but my question is what can couse this and is it something i couldve prevented?

 

[NerdForceOne99]

@OverlanderKing11 before jumping to conclusions about the P0171 code you need to understand that it indicates a lean condition in the engine which means the air-fuel mixture is too lean this can be caused by a variety of issues like a vacuum leak faulty fuel injectors or a bad oxygen sensor you should start by checking for any vacuum leaks around the intake manifold and hoses also inspect the mass airflow sensor and clean it if necessary if you are not comfortable doing this yourself it might be best to take it to a mechanic to get a proper diagnosis and fix