My 97 740il wont pass emissions! replaced sparkplug, fuel filter, o2 sensors, new cat, still no passing smog. i also ran a fuel injector cleaner and a sure-emissions pass additive and no cigar. any information will help. thanks!

What are the emission levels? Which particular contaminant are you having problems with? Also, how was the car prepped before the test? Was the catalytic converter nicely warmed up? How long has it been since you replaced all those components?

My experience is that the BMW software takes a long time to adjust itself to new emissions equipment. For example, when I replaced the two cats on my '95 525i and had it tested just 2 days afterwards, it barely passed NOx and it didn't run that strongly. Now it's fine. I suspect that the new cats flowed better so the car was running lean until it "learned" and modified its air-fuel maps. BTW, it took at least 2-4 weeks before I noticed the car returning to normal--and that was with a lot of in-town driving and at least one long freeway trip.

My experience is that the BMW software takes a long time to adjust itself to new emissions equipment. For example, when I replaced the two cats on my '95 525i and had it tested just 2 days afterwards, it barely passed NOx and it didn't run that strongly. Now it's fine. I suspect that the new cats flowed better so the car was running lean until it "learned" and modified its air-fuel maps. BTW, it took at least 2-4 weeks before I noticed the car returning to normal--and that was with a lot of in-town driving and at least one long freeway trip.
Anytime there's any work done that could affect mixture adaptation a part of the job should include a reset of the adpation values in the DME.