Code 4 is related to air injection system(smog pump). Code 9 is for the intake air temp sensor(behind lt headlamp).
4 seconds to bring up the code & 8 seconds to erase would be correct.
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)