Also,

I just tested the duty cycle this morning.

Here are my results.

With the ignition set to position 2: 69.3%

Reading at first start with cold engine: 49.8%

Reading within 3-4 minutes of start-up started to climb from 49.8% (49.8% --> 54.5% --> 75.8% --> 80.9% --> 84.9%) and eventually settled between a fluctuation of 92.3% and 92.7%.

So from what I understand, the car is properly running in open loop (warm-up) mode. The car also transitions to closed loop (hot engine) mode just fine. but my mixture setting is way off which is why it settles at 92.3%?

Can I rule out a bad EHA and vacuum leaks?

__________________
2006 BMW M5 "Heidi" @ 109,000 miles
2005 MBZ C55 AMG "Lorelai" @ 165,000 miles
1991 MBZ 300E "Benzachino II" @ 165,000 miles
1990 MBZ 500SL "Shoshanna" @ 118,000 miles

(On the hunt for a good used M103 engine as of 6/10/23, PM me if you have one to sell!)