mini cooper s

    I have a Mini Cooper S and race in T4 and STU for past 2 years, the car still has its Cat converter and mufflers which I want to remove, actually cat overheating seems to place the car in limp mode, thus it needs to go.  What impact does this have with o2 sensor, and any other  impact to the ECU. Mini/Bmw guys must have done this, please let me know what you did.  Do you leave the o2 sensor in the exhaust or did you defeat it somehow.





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    • Austin R Hilliard

      you will HAVE to keep the O2 sensor, unless you have an aftermarket ECU.  p.s. Not a BMW guy, but just have some knowledge of how ECU's work.  I believe most of the ECU's now are using wideband O2's, and typically there are 2 in the exhaust, 1 just after the headers and 1 farther down the line.  You'll have to keep both I would assume.  A standard aftermarket header-back exhaust should retain both of them.


      Thanks for the response, I actually figured it out myself, I bought nice little units that fool the ECU into thinking the O2 sensors are reading acceptable values with the Cat replaced.