Multiple misfires after installing downpipes

Xyruss · 04-20-2014, 03:14 AM

I have just installed my VRSF downpipes and i started the car up before putting the steering rack back up and reinstalling the belly pan. At start up it was good. i let it warm up for a while and then gave it a little throttle. after the car was warmed up it went into a rough idle. I plugged into my JB4 and i am getting multiple mis fires. didnt have this issue before the install.

Is this due to possibly incorrectly installing O2 sensors? maybe I need to change maps? Im on map 1. I am also low on fuel... Im just wondering if anyone has any experience. would like to know before I reinstall belly pan.

I noted the color of O2 sensors and I put the ones with the grey sheath in the front turbo downpipe and the ones with the balck sheath put into the rear turbo downpipe.

AWil335i · 04-20-2014, 08:39 AM

You probably have them swapped... each plug goes to a specific bank

Xyruss · 04-20-2014, 11:23 AM

Okay well i just checked again and im only misfiring in cylinders 1 3 and 5. could someone help me and tell me which turbo corrresponds to those cylinders? Ill check my connections again once i know. I there any way to clean the O2 sensors? I was pretty careful with them so i dont see how they could have gotten damaged

Xyruss · 04-20-2014, 11:38 AM

I think I have the front sensors swapped. from searching it seems the black one is suppsoed to go on the front turbo.. why would bmw mix them up like that. so confusing

04-20-2014, 03:14 AM	#1
Xyruss Enlisted Member 6 Rep 39 Posts Drives: 2009 monaco blue 335i Join Date: Sep 2013 Location: Edmonton, Alberta iTrader: (0)	Multiple misfires after installing downpipes I have just installed my VRSF downpipes and i started the car up before putting the steering rack back up and reinstalling the belly pan. At start up it was good. i let it warm up for a while and then gave it a little throttle. after the car was warmed up it went into a rough idle. I plugged into my JB4 and i am getting multiple mis fires. didnt have this issue before the install. Is this due to possibly incorrectly installing O2 sensors? maybe I need to change maps? Im on map 1. I am also low on fuel... Im just wondering if anyone has any experience. would like to know before I reinstall belly pan. I noted the color of O2 sensors and I put the ones with the grey sheath in the front turbo downpipe and the ones with the balck sheath put into the rear turbo downpipe.
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04-20-2014, 08:39 AM	#2
AWil335i Second Lieutenant 12 Rep 281 Posts Drives: 2007 E92 335i Join Date: Oct 2012 Location: Indianapolis iTrader: (0) Garage List 2007 BMW E92 335i [0.00]	You probably have them swapped... each plug goes to a specific bank __________________ 07 E92 335I \| JB4 G5 ISO \| BMS E85 Flash \| DCI \| BMS DPs \| Helix FMIC \| Alpina TCU Flash \| Walbro GLS392 \| E70 \| 429rwhp/474rwtq \|
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04-20-2014, 11:23 AM	#3
Xyruss Enlisted Member 6 Rep 39 Posts Drives: 2009 monaco blue 335i Join Date: Sep 2013 Location: Edmonton, Alberta iTrader: (0)	Okay well i just checked again and im only misfiring in cylinders 1 3 and 5. could someone help me and tell me which turbo corrresponds to those cylinders? Ill check my connections again once i know. I there any way to clean the O2 sensors? I was pretty careful with them so i dont see how they could have gotten damaged
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04-20-2014, 11:38 AM	#4
Xyruss Enlisted Member 6 Rep 39 Posts Drives: 2009 monaco blue 335i Join Date: Sep 2013 Location: Edmonton, Alberta iTrader: (0)	I think I have the front sensors swapped. from searching it seems the black one is suppsoed to go on the front turbo.. why would bmw mix them up like that. so confusing
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