02-05-2024, 05:54 PM | #1 |
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P0156 / 2C78 error code won't go away
I'm losing my mind over this issue. I've been getting the error code for the Bank 2 Sensor 2 (after catalytic convert) o2 sensor for ages. I've already replaced the sensor with a brand new one. But no matter what I've tried the error code will not go away. Each time I clear it, it just comes back on almost immediately after starting it back up.
My bimmerlink app shows me the 2C78 code, while my NT530 tells me it's P0156. I'm attached photos/screenshots of everything, just in case something might stand out to any of the experts who might be reading. Also worth mentioning, occasionally on immediate startup, it will smell odd. Kind of like paint chemicals. Maybe related to the sensor giving bad readings to the computer? 2012 X5M, 137k miles. |
02-06-2024, 06:10 PM | #2 |
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P codes are useless for BMWs. Stick with Bimmerlink or better.
Not an S63 expert, so take what I say with a grain of salt. Hopefully an N63 expert can chime in. Post cat O2 codes won't do anything but cause you to fail emissions testing if you have it. They don't change how the engine operate, they only tell you whether your cats are working or if your sensor is broken. So don't worry about anything negative happening to the engine. What brand sensor are you using? I've heard that a lot of BMWs are very sensitive to brand and I believe that OE is Bosch. Last edited by jbash87; 02-06-2024 at 06:17 PM.. |
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StradaRedlands5947.50 |
02-06-2024, 08:14 PM | #3 |
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Have you checked the downpipe where it bolts to the mid pipe section? If that’s loose or not sealed well, it’s possible that air could be mixing in and causing a bad reading. It could also cause a bad temperature reading too.
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StradaRedlands5947.50 |
02-13-2024, 04:32 PM | #5 |
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Okay so I received the new o2 sensor below, and reset the error. It still came back on.
https://www.rmeuropean.com/Products/...125-MFG14.aspx So now all I can think of to do is check the downpipes to see if anything is loose. |
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