You may go to start your car and see the check engine light is on and the engine is running rough. After grabbing and connecting your handy OBD II scan tool or code reader, you find out you have a P0171 code. We’ll review what this code means, how serious it is, and how to diagnose it yourself.
Video: Check Engine Light? System Too Lean – Code P0171, P0174
Watch this video for expert mechanic help diagnosing P0171 code causes, and keep reading for more details: