330I CODE P122D RPM 500-700 DROP Rough Idle

330istocknot · 03-04-2017, 03:57 PM

Hi All,

Searched and only 2 useless post regarding this issue/code.

Symptoms, Check Engine light on.

1. Car struggles to turn on at mornings, on first start.

2. Recently after car is on, the RPMs drop between 500-700 and car has a really rough idle as if it was about to stall, then i accelerate a little and RPMs go back to normal.

I was reading online that it might just need an o2 censor, if so which one? i know there are 3 different ones i believe.

Anyone gone through this? simple fix? recommendations? TIA

aj90 · 03-04-2017, 05:15 PM

Might be an ignition coil. Mine went bad and I had similar symptoms to you.

Flyboy161 · 03-04-2017, 08:00 PM

OBD 2 readers have a tough time with BMW's. apparently they don't speak German. At a minimum get the Carly app and their Gen2 adapter, and read the codes. They'll be a little more specific. Best bet is to read the codes with INPA. P122D is too generic a code.

03-04-2017, 03:57 PM	#1
330istocknot First Lieutenant 186 Rep 394 Posts Drives: 330chino Join Date: Mar 2016 Location: chino iTrader: (0)	330I CODE P122D RPM 500-700 DROP Rough Idle Hi All, Searched and only 2 useless post regarding this issue/code. Symptoms, Check Engine light on. 1. Car struggles to turn on at mornings, on first start. 2. Recently after car is on, the RPMs drop between 500-700 and car has a really rough idle as if it was about to stall, then i accelerate a little and RPMs go back to normal. I was reading online that it might just need an o2 censor, if so which one? i know there are 3 different ones i believe. Anyone gone through this? simple fix? recommendations? TIA
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03-04-2017, 05:15 PM	#2
aj90 Budget Builder 37 Rep 114 Posts Drives: 08' 335i, 17' 330i, 18' 440i Join Date: May 2016 Location: Placentia, CA iTrader: (3)	Might be an ignition coil. Mine went bad and I had similar symptoms to you.
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03-04-2017, 08:00 PM	#3
Flyboy161 Second Lieutenant 288 Rep 293 Posts Drives: 2008 E93 M3 Join Date: Apr 2014 Location: Perry, GA iTrader: (0) Garage List 2008 BMW M3 [0.00] 2012 BMW E92 335i [0.00]	OBD 2 readers have a tough time with BMW's. apparently they don't speak German. At a minimum get the Carly app and their Gen2 adapter, and read the codes. They'll be a little more specific. Best bet is to read the codes with INPA. P122D is too generic a code.
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