Asking again? Why does the CC's startup RPM decrease so slowly? Other cars stabilize at idle in about 30 seconds, but it feels like the CC never comes down. Is it designed that way?

10 Mazda 3 Star Version 2.0 frequently has the warning light on, with an instant fuel consumption of 30-40 at startup. Spark plugs, intake manifold solenoid valve, rear oxygen sensor have been replaced, throttle body and mass air flow sensor have been cleaned, but the light comes on again. The first row mixture is too lean. Any suggestions?

Braking Dipping. I'm considering getting a standard 911. After a test drive of the 4S, I noticed a braking dipping issue. Even if I slowly release the brakes at the last moment, there's still a forward lurch just before coming to a stop. My current Mercedes doesn't have this issue, and neither did the Panamera I test drove earlier. Is it a matter of selecting the wrong mode, or is the car designed this way?