I see several breaks in the webbing, which would seem to indicate that over extruding may not your problem.
Have you tried going back to basics and printing a few calibration cubes? There are also some test patterns that print a single layer with 100% infill they will help give us an idea if your nozzlel setting and extrusion rates are correct. For extrusion you really need to make measurements to know for sure--- do you have the tools to do so?and if you have the tools have you verified filament diameter, extruded diameter (nozzle size), and extrusion rate??
Also, it looks like the retraction settings could be better. I do not usually get stringing when printing with ABS. This could be related to temperature.
Are you still using the stock extruder?