99 740i - Check engine light

1999 740i 142000miles, check engine light came, pulled code “multiplicative catalyst mixture adaptation control limit reached”. Replaced both front oxygen sensors and code came back, any ideas?

My 2001 750iL also had check engine light yesterday, code reader say P0171 System too lean. Brought it to a indy shop, and the guy there suggested me to clear the code first then drive for a couple days to see if the code comes back. Do you know if that is a good idea? As I understand, if the car really has problem, it might hurt the emission system pretty bad if I keep it running. So can anyone give me some suggestions? Thx

If you have access to a exhaust gas analyzer check mixture strength. Rich costs extra gas; Lean costs valves (those ones in the head). An injector clean may be the way to go. Bad spray patterns etc will upset the O2 sensors.