I'm going to take all of your info to a new independent local MB mechanic.

I really appreciate the help, and I will definitely follow up with the diagnosis, repair, and how the old benz is running (always nice to have those at the end of the posts!) !

FWIW, I did have two other codes that appeared once last week, and haven't returned.

PO4032
PO4022

They are "inefficiencies" of the Left & Right Catalytic Converters. Car hasn't stumbled in awhile.... and it definitely is more severe/problematic after a long run or such when the engine is NICE & WARM!

Thx again

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)