Both of my toilets bubble when one is flushed! So,I just had the septic system cleaned out & a new pump put in. The house was built so that there are is an air trap/vent under the kitchen sink & in one bathroom. No vent for plumbing on the roof. I replaced the little screw on vents. Both of the toilets still bubble violently when either one is flushed! There is no septic smell to the air that comes out. I'm at wits end, perhaps one of those augers? Any ideas?