o2 sensor help
 

Gents....anyone ever do a o2 sensor replacement yourself instead of going to the dealer.......i need help as far as location of sensors and if they need programming after installing.....thanks guys

ok, let's start with your x5 specs, you have 3.0 or 4.4? They have different location so it really matters if you can provide that. This is an easy DIY as long as you have the right tools.

2003 3.0 x5......any diagrams or step by step instructions would be great.

thanks

they are located on the post catalytic converter. You will need crowfoot wrench or BMW special tool 22mm slotted socket. Diagram has to wait though since i only use my iphone at this time, my apologies.

even the 3.0 X5 has pre and post cat O2 sensors. (should be 4 in total, 2 before catalyst and 2 after.)

Unless the post cat sensors are throwing a code I would leave them as they don't make any difference in fuel economy nor do they make any difference in performance. Post Cat o2 sensor only monitor catalyst efficiency! Save your money unless you Really want to do it!

You won't need to have them reprogrammed, and you'll only need to reset an engine light if it is on. Other than that I'll leave the diagrams and instructions to someone else that has them.

4 converters? I thought there are only two 1 pre- 1 post cat converter.

Not 4 convertors - 4 sensors !

Bear in mind there are 2 different kinds one for pre cat and other part number for post cat.

More re same here http://www.xoutpost.com/x5-e53-forum/43873-bank-1-a.html

SES/engine light illuminates for various emission based issues including if one of these fails - you then have to find out the code to see if its an o2 sensor and if so which one.


If all well then leave well be - spend money on something more fun !

There are two cats and four sensors on the 3.0. I tried to do this replacement myself and gave up pretty quick when I found where all of them were located. The two pre-cat sensors are loacted just to the left (facing the vehicle) of the engine right after the manifold. The post-cat sensors are located behind the right front wheel - you can see them by crawling under the vehicle, but you probably need to remove the wheel and fender liner to get good access to them.

FYI, if you ever have to replace the cats, get ready to shell out some money. The cats are basically mounted to the manifold and there are no aftermarket solutions out there - cost me $2200!! My indy mechanic said that was the first and last one he will ever do - they actually had to loosen some of the motor mounts to access the manifold.

Something to look forward to (NOT).... !