So..... firstly, Lester now has his bmw back up and running after over a year and several thousand dollars of “hunting the issue” style of bmw repair strategy (coils,plugs,fuel pumps,o2 sensors.... the list goes on) . I seriously wonder how some “head technicians” get their jobs within Bmw.
initial scan of the m3 came back with the following codes (in the picture). Did some googling, and found out that the cat code is Indeed the cause of the limp mode, but what was causing it? Cleared it all off, took the car for a drive and as expected, went onto limp mode along with the cat code and o2 codes coming back
during this drive, love data on the scanner showed that the o2 sensor voltage values were NOT changing, which was totally odd
as you can see, ALL 4 Sensors have the same heater error...... put everything nag together and was like, surely if all 4 sensors have the same error.... it must be a common something connected to all 4.
First thing first, checked the o2 sensor fuse.... wouldn’t you know it.... it was blown ? as a result, the heaters were not working and the sensors were not reading as they should have been...... in turn triggering the cat protection codes because of the “lean readings” in relation to rpm
some things are not hard to use half a brain and figure out.... and how Bmw have now been able to use 1/20th of a single brain cell to follow the dead obvious signs fails to amaze me
I suspect that what has happened is one of the original O2 sensors has failed, shorted and taken the fuse with it creating the further errors when the new ones were installed
but anyway, problem solved!