None of your listed codes have anything to do with a bad gas cap!

They are all O2 sensor related. Bosch suggests that their sensors are good for 100K miles, after that they can fail at any time.

Can't imagine anyone paying $40 for a gas cap...can't imagine the dealer marking it up 200% either!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator