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P0172

Posted: Mon Sep 25, 2023 6:19 pm
by Gn22
Hi, P0172 almost new MAF sensor replaced 05-23 O2 sensor replaced both sides Upstream with NTK 18 months ago. Air filter new. Smoke test and no leak found. When I reset the ECU, the car is running well Any help would be appreciated. THANK YOU.

Re: P0172

Posted: Mon Sep 25, 2023 9:20 pm
by VStar650CL
That's a very unusual code, it's the opposite of a vacuum leak. The ECM is trying to lean bank1, not rich it. Normally that's an issue with one or more of the injectors, but normally that also means some sort of miss or rough running. Fuel pressure or MAF problems would be affecting both banks. Since you're not getting any of that, my first guess would be that your bank1 A/F Sensor (front O2) is lying to the ECM.

Re: P0172

Posted: Tue Sep 26, 2023 7:34 pm
by Gn22
OK Thank You, I will replace bank1 A/F Sensor to see what happen.

Re: P0172

Posted: Sat Oct 14, 2023 5:29 pm
by Gn22
Hi, after 2 weeks that I replaced bank1 A/F Sensor (front O2) with Denso so far so good thank you VStar

Re: P0172

Posted: Sat Oct 14, 2023 5:40 pm
by VStar650CL
You're most welcome, happy to help. Happy motoring!