My guess is that the rubber donut seals around the injectors you pulled are not properly sealing after being disturbed. These will dry out and harden from heat and age and should be replaced frequently. They are also very cheap. The clamps that hold the injectors in place on the 190e do not put a lot of pressure on these seals. You likely now have a vacuum leak on these 2, which you wont notice at higher engine speeds, but will at idle.