Hello,

Hope someone can help. Have a 2016 Accord Sport 2.4 that started throwing code P0171- System too lean Bank 1. Anyone have experience with this and willing to share what the remedy was. I've cleaned the MAF sensor and don't hear a vacuum leak at this point. My next move was to replace O2 sensors. And correct me if I'm wrong, but this motor only has one bank?

Thanks in advance...

 

Your motor only has one bank.

P0171 only means that the engine computer is detecting too much oxygen in the exhaust. The actual problem can come from an intake vacuum leak, faulty MAF sensor reading, exhaust leak, bad upstream O2 sensor, fuel delivery issue.

You can throw a lot of parts at this problem and not solve the root cause. Plus, I've read posts on here where a new aftermarket part didn't work out of the box, and makes diagnosis more difficult.

I recommend purchasing an obd2 scan tool that can read live engine data. You will need to look at fuel trims to see how the engine is managing the air/fuel ratio, air flow through the MAF, O2 sensor reading, etc. We can walk you through some tests to try, then it will help narrow down the problem. A scan tool is now almost a necessary tool for DIY work, where you only needed a shop manual and a volt meter on older vehicles for most DIY work.