"the car starts 1st key/no pedal immediately when cold"

This does tell us something. It tells us that your basic mixture setting is about ten times what is necessary for closed loop.

If measured with a gas analyser I imagine you are running 3-5% CO. ... all the time!

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician