As we know BMW E39 was manufactured in 1995 and introduced to the USA in 1997, so it is equipped with OBD 2 System; BMW E39 belongs to the basis of the 5 series; it runs until 2004 after the BMW E60/E61 manufacture. Dual manifolds from the engine and two converters present four oxygen sensors in the E39's exhaust system. The two front sensors monitor the spent fuel to air ratio and the two rear sensors monitor the emissions post catalytic converter. They transmit the data by voltage signals to the computer in the engine. If there is a trouble in the data, the computer will trigger the malfunction indicator light and the "check engine" light.
You'll Need OBD 2 code reader/scanner and trouble Code guide for this job
Find out the diagnostic link connector (DLC) for the BMW E39. It is generally located under the driver's side instrument panel near the steering wheel post.
Insert the OBDII code reader into the DLC.
Turn the ignition key to the key on/engine off position. This is two clicks forward in the ignition that activate the electrical components but does not launch the engine.
Read the menu item of the
OBD 2 code reader. Use the scroll buttons on the face of the code reader to maneuver through the menu options. Select the "Read Codes" option and press the "Enter" button. This option will take a moment to send the command the computer of the engine. When it has communicated and discovered the status of the diagnostic trouble code (DTC), it will display the universal code with a brief description on the screen of the code reader.
Compare the information of the code to confirm the oxygen sensor or sensors that have failed to the code guide (It is usually supplied with the code reader in user manual). The brief description on the menu of the code reader (relying on the individual code reader) may even indicate which sensor has failed or found out a problem. There are a lot of online stores over the internet; you can find that what you need online.
