Print Page | Close Window

O2 sensor

Printed From: Bavarian-Board.co.uk - BMW Owners Discussion Forum
Category: Technical & Model Specific Forums
Forum Name: BMW ///M Power
Forum Discription: Ask your BMW M Power Technical Questions here (M1, M2 hybrids, M3, M5 & M6)
URL: http://www.bavarian-board.co.uk/forum_posts.asp?TID=33256
Printed Date: 08-May-2024 at 21:04


Topic: O2 sensor
Posted By: kevs635csi
Subject: O2 sensor
Date Posted: 09-September-2006 at 19:02
my car runs like a bag of sh*t when cold for the first minute or so & even when warn i get low speed jerking & popping back on the over run at lowish revs, but it  runs much better ,smoother &  quicker with the o2 sensor disconnected & i get none of the symptoms above ,obviously it needs a new one ,its a bit of a mare to get the old one out ,the ecu goes to default mode & calculates a substitute value  what are the longterm effects of running it with the sensor off ,

-------------
cool as the fonz!!



Replies:
Posted By: stevesingo
Date Posted: 10-September-2006 at 07:52
Kev, When the engine is cold it does not use the O2 sensor. The 02 sensor only comes in to effect when warm, over say 70deg and therefor should not effect your cold start.

I'd have a look at your coolant sensor first. I had a problem simipar and it turned out to be a damp connection to the coolant sensor.

Steve



Posted By: kevs635csi
Date Posted: 10-September-2006 at 13:56
i changed that sensor not long ago

-------------
cool as the fonz!!


Posted By: SHEPSM3
Date Posted: 11-September-2006 at 11:45

Kevin, I have my Oxy sensor disconnected too, so I could remap all the part throttle fueling sites without the sensor messing up what I just put in.

You have to be carefull with what you say these days on these forums, but i don't think it would cause any damage long term unless you still have the cat fitted, if so this may suffer? If not then its better than your sensor reading wrong and putting a lean mixture into your engine, or vica versa.

The ultimate fix though, as you know is to replace the sensor.

I'd advise to check the fueling on a dyno....try Westec in Newport.



-------------
[IMG]http://i4.photobucket.com/albums/y135/ShepsM3/New-1a1.jpg">[IMG]http://i4.photobucket.com/albums/y135/ShepsM3/New-1b1.jpg">


Posted By: kevs635csi
Date Posted: 11-September-2006 at 19:54
ok thanks for that i decatted last year so thats no problem ,i think its over fuelling to be honest as the exhaust fumes  smell rich when cold pops back on over run too with it connected & disconnected

-------------
cool as the fonz!!



Print Page | Close Window