HELP:CEL and p0171 code
 

Hi, guys, I just running buttonwillow last friday and Im out of track on Bus Stop,after that my car have CEL and when idle the car will drop RPM to 600 then back to 900(which is normal), and it will do this three times then engine will shut down by itself.



i check the code it said the system too lean, and when i open the hood i hear a lot of air sound from the right side of engine.



I running OFT E85 tuning, PLM longtube header and TRD air intake on track day, right now im already back to stock tune, OEM air box and header, then i go to Subaru today, after they check they just said my air box lose one bolt and said talk a lot i install OEM air box is wrong and need me back to "REALLY STOCK" then they can check my car.... really no idea what are they thinking.



anyone have these problem before? plz help me, thanks.

[ame="https://www.youtube.com/watch?v=dwQk_r9LQ8M"]test - YouTube[/ame]

[ame="https://www.youtube.com/watch?v=QxSsN-U5_KE"]test2 - YouTube[/ame]

You might want to go over your first post, it is quite hard to read. I googled the code and it says it is lean code. You said you are running an OFT E85 tune, did you take any logs? Have you played with the MAF scaling or changed supplier of your E85 prior to this? After you installed the stock airbox were the symptoms still there? Have you checked the header for leaks?

I should add I can't view your videos from the computer I am currently on so I apologise if the questions i ask are answered there.

If the car has been running fine on that setup for a while Its likely you have developed an air leak in the intake or exhaust header. eg crack in header or leak at gaskets at engine or where header connects to overpipe.

did your o2 sensors screw in easily most times you need to clean header threads with tap\chaser.

take some logs and look for lean afr or high fuel trims at low rpm.

dealer will blame your aftermarket parts and tune so dont even think about taking it to them unless you return it to stock on petrol

I had a friend throw this exact code after spinning out on the track last year, it ended up being a vacuum leak from one of the lines under the intake manifold. It was just disconnected so we plugged it back in on the spot.

Since it sounds like a vacuum leak in your video, try spraying some liquid or brake cleaner into the engine bay and trace it back to the leaking hose.

The vacuum lines under the intake manifold aren't clamped on at all. You can get to these easily if you unbolt the A/C compressor and move it out of the way, (don't disconnect A/C lines). That's probably what it is.

Thanks guys, try tmrw


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Finally dealer fix it, they said there some oil in the MAF and destroy it and replace a new one for me


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