Front\First\Before Cat NOX Sensor 004BB2 Error Code

Greck · 08-16-2016, 11:26 PM

Do I need to replace the front NOX sensor? This code always come back after several days. Any suggestions where I can get it cheaper? Thank you.

Greck · 08-16-2016, 11:27 PM

Is there is a way to clean or fix it somehow?

Yozh · 08-17-2016, 12:16 AM

Recently, floyd posted that he has found out that a failed thermostat would result in a car running cool and thus would prevent proper SCR system functioning and triggering SCR related error codes. Check what temperature your car is running at.

floydarogers · 08-17-2016, 01:18 AM

Quote:

Originally Posted by Greck

Do I need to replace the front NOX sensor? This code always come back after several days. Any suggestions where I can get it cheaper? Thank you.

How many miles? Remember, these things have a limited lifetime - supposed to be around 100K miles, perhaps 120K miles?

I never found them much less than the dealership charged for them.

Quote:

Originally Posted by Yozh

Recently, floyd posted that he has found out that a failed thermostat would result in a car running cool and thus would prevent proper SCR system functioning and triggering SCR related error codes. Check what temperature your car is running at.

Definitely should check temperature. Also, the SCR metering valve (injector) on the bottom of the DPF/OxyCat canister needs to be checked (if not already).

Thecastle · 08-17-2016, 06:04 AM

had mine replaced at 50K miles. if you read here on the forums you'll see these sensors fail frequently. There is no cleaning that can be performed that I'm aware of to restore functionality and in many cases both sensors will need to be replaced.. The car checks the sensors for plausibility, by disabling the scr and verifying that both sensors before and after the scr read the same. But of course rule out other causes first like low temp, as a thermostat is cheaper.

Greck · 08-17-2016, 08:47 AM

Temp is 95C, so it is good. Metering valve is good too and PASS the ISTA tests and I cleaned it several weeks ago and I changed the DEF in the system, fuel filter and other filters.

Greck · 08-17-2016, 10:07 AM

Quote:

Originally Posted by floydarogers

How many miles? Remember, these things have a limited lifetime - supposed to be around 100K miles, perhaps 120K miles?

111k miles

Greck · 08-17-2016, 10:19 AM

Is that is one that I need http://parts.bmwofbridgewater.com/p/...628576471.html ? Thanks.

08-16-2016, 11:26 PM	#1
Greck Second Lieutenant 59 Rep 245 Posts Drives: e90 2011 335d / e70 2011 35d Join Date: Jul 2016 Location: CA, Bay Area iTrader: (0)	Front\First\Before Cat NOX Sensor 004BB2 Error Code Do I need to replace the front NOX sensor? This code always come back after several days. Any suggestions where I can get it cheaper? Thank you. Attached Images
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08-16-2016, 11:27 PM	#2
Greck Second Lieutenant 59 Rep 245 Posts Drives: e90 2011 335d / e70 2011 35d Join Date: Jul 2016 Location: CA, Bay Area iTrader: (0)	Is there is a way to clean or fix it somehow?
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08-17-2016, 12:16 AM	#3
Yozh Colonel 870 Rep 2,615 Posts Drives: 2011 335d M-Sport Join Date: Mar 2014 Location: Wet Coast iTrader: (4)	Recently, floyd posted that he has found out that a failed thermostat would result in a car running cool and thus would prevent proper SCR system functioning and triggering SCR related error codes. Check what temperature your car is running at.
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08-17-2016, 06:04 AM	#5
Thecastle Major 307 Rep 1,146 Posts Drives: F10 550i Join Date: Apr 2015 Location: Houston, TX iTrader: (0) Garage List 2020 BMW M340i [0.00] 2019 RAM 3500 [0.00] 2020 BMW X3 [0.00] 2016 BMW 550i [0.00] 2000 Ford F450 7.3l ... [0.00]	had mine replaced at 50K miles. if you read here on the forums you'll see these sensors fail frequently. There is no cleaning that can be performed that I'm aware of to restore functionality and in many cases both sensors will need to be replaced.. The car checks the sensors for plausibility, by disabling the scr and verifying that both sensors before and after the scr read the same. But of course rule out other causes first like low temp, as a thermostat is cheaper.
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08-17-2016, 08:47 AM	#6
Greck Second Lieutenant 59 Rep 245 Posts Drives: e90 2011 335d / e70 2011 35d Join Date: Jul 2016 Location: CA, Bay Area iTrader: (0)	Temp is 95C, so it is good. Metering valve is good too and PASS the ISTA tests and I cleaned it several weeks ago and I changed the DEF in the system, fuel filter and other filters. Last edited by Greck; 08-17-2016 at 10:05 AM..
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08-17-2016, 10:19 AM	#8
Greck Second Lieutenant 59 Rep 245 Posts Drives: e90 2011 335d / e70 2011 35d Join Date: Jul 2016 Location: CA, Bay Area iTrader: (0)	Is that is one that I need http://parts.bmwofbridgewater.com/p/...628576471.html ? Thanks.
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