On my 2001 E320 AWD wagon [94K] I'm getting these 2 codes only:

P0422 - Main Catalyst Efficiency Below Threshold (Bank 1)
P0432 Main Catalyst Efficiency Below Threshold (Bank 2)

I've cleared the codes often and within 15 restarts they reappear again with the CEL staying on till I clear it again.

Work recently done:
new battery
new Bosch spark plugs +2
New air filter
Cleaning of the MAF with CNC cleaner
High test gas only

Wagon runs strong with no hesitation at all but the CEL reappears with the same messages:
P0422
P0432

Help with any suggestions at this time!