Just 2 days ago, I brought my Honda Fit GE6 for it's regular 10,000km servicing. Today, the check engine light came on and showed code P0171 System Too Lean (Bank 1). Before the check engine light came, fuel consumption was at 14km/litre and dropped to 12km/litre after the light came on. Below is a list of maintenance work done.

1) Engine Oil
2) Oil filter
3) CVT Transmission fluid
4) Spark plugs

Did my mechanic screw up somewhere during the maintenance? Or is it a coincidence that my O2 sensor failed? Total mileage is at 147K.

Please tell me it's something I may be able to figure out and fix myself. Any advise is appreciated.

 

Since you have to disassemble the entire intake system down to the runners to service the plugs, odds are there’s a vacuum leak somewhere. Check for loose or disconnected hoses. Make sure all the connections from the air box to the manifold are tight. If you have an obd scanner you can get real-time airflow and manifold pressure readings too.