Engine problem
2001 Other BMW models V8 Two Wheel Drive Manual 52000 miles
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i have a 2001 bmw 540i when i gas it hard it studders at 4000 rpm for a second and then goes on. i scanned it and it gave me a code for a faulty left pre cat o2 sensor. what do you think is causing this hesitation.

there is a possibility that the pre cat sensor is causing the problem, and if it is setting a fault then it should be addressed first, we can then go about addressing the stuttering at 4000 rpms issue. BTW, what method was used for obtaining the fault code?