can you help clear some confusion on my exhaust setup..

Jet1990 · 03-07-2016, 08:09 AM

Hi all,

im thinking about decatting my car as theres an error showing up that the nitrogen oxide catalytic converter is ageing. Got the car on the ramp over the weekend and i cant get my head around a few things. Apparently this car has 4 cats. 2 on the manifold and 2 underneath the body. Now heres the stupid question. are those two silencers in the pic with a cat at the back or is it the other way round with 2 cats and a silencer. Ive circled the two sensors which i assume are the Nox and 02 sensor but i always thought the nox was after the cat but this sensor is before what i think is the cat.

anyone care to chime in?

cheers

Jet1990 · 03-07-2016, 08:18 AM

Another pic of what i think is the cat with the nox sensor but this is plugged in before the cat.

Aragorn30d · 03-07-2016, 08:37 AM

The two round cans side by side are cats, the single box is a silencer

http://www.realoem.com/bmw/enUS/show...diagId=18_0739

Theres also more cats on the exhaust manifold:

http://www.realoem.com/bmw/enUS/show...diagId=18_0741

Sensors are depicted here:

http://www.realoem.com/bmw/enUS/show...diagId=18_0722

The NOX sensor looks to have a short lead to an electronics box.

03-07-2016, 08:09 AM	#1
Jet1990 Private First Class 15 Rep 107 Posts Drives: 330i M Sport Join Date: Feb 2016 Location: yorkshire iTrader: (0)	can you help clear some confusion on my exhaust setup.. Hi all, im thinking about decatting my car as theres an error showing up that the nitrogen oxide catalytic converter is ageing. Got the car on the ramp over the weekend and i cant get my head around a few things. Apparently this car has 4 cats. 2 on the manifold and 2 underneath the body. Now heres the stupid question. are those two silencers in the pic with a cat at the back or is it the other way round with 2 cats and a silencer. Ive circled the two sensors which i assume are the Nox and 02 sensor but i always thought the nox was after the cat but this sensor is before what i think is the cat. anyone care to chime in? cheers Attached Images
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03-07-2016, 08:18 AM	#2
Jet1990 Private First Class 15 Rep 107 Posts Drives: 330i M Sport Join Date: Feb 2016 Location: yorkshire iTrader: (0)	Another pic of what i think is the cat with the nox sensor but this is plugged in before the cat. Attached Images
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03-07-2016, 08:37 AM	#3
Aragorn30d Lieutenant Colonel 175 Rep 1,596 Posts Drives: E90 330d Join Date: Mar 2015 Location: Fife iTrader: (0)	The two round cans side by side are cats, the single box is a silencer http://www.realoem.com/bmw/enUS/show...diagId=18_0739 Theres also more cats on the exhaust manifold: http://www.realoem.com/bmw/enUS/show...diagId=18_0741 Sensors are depicted here: http://www.realoem.com/bmw/enUS/show...diagId=18_0722 The NOX sensor looks to have a short lead to an electronics box.
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