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Matt, Engineer
Category: BMW
Satisfied Customers: 21608
Experience:  Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing
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I had work done on 99 Bmw, also replaced o2 sensors, now o2

Customer Question

I had work done on 99 Bmw, also replaced o2 sensors, now o2 sensor monitor does not want to reset, was told I need to drive it for awhile but put over 1000 miles & still have not reset! Any suggestions?
Submitted: 7 months ago.
Category: BMW
Expert:  Steve replied 7 months ago.
Hello and welcome,
My name is ***** ***** it will be my pleasure to assist you today.
Miles alone is not sufficient, you need to complete specified drive cycles that have many requirements before the monitors will reset. I can email the drive cycle info to you if you would like it
Customer: replied 7 months ago.
I have the drive cycle instructions & I have completed them many times everything resets except the 02 sensors monitors!
Expert:  Matt replied 7 months ago.


one thing to check is the type and Part number of the O2 sensors as there are quite a few types and if the resistance isn't right then the sensor OBD will never reset