Should be for the life of the car unless the car was HIT in the left fender!! Never replaced one for any other reason!!
YES disconnect the line at the check valve & block off while checking the duty cycle.
AS long as you have a good duty cycle at idle & at 2500 the car will give you as good performance as it would if they were excatly the same reading.
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)