Brittanicvs

Our space has an Ultimaker 2 that, up until a month ago, was working great until someone used 1.8mm ABS with it and on top of feeding issues the filament broke in the Bowden causing a serious jam. I was using 2.85mm Ultimaker filament on it with no problems. The Bowden was replaced (twice), but now I can't get anything to feed through it. I've tried the atomic cleaning method (https://ultimaker.com/en/community/5118-blocked-nozzle), and snaked a few strands of fine-gauge wire through the nozzle. Any other recommendations? I was hoping I wouldn't have to take it all apart just yet, but I haven't looked at the PTFE coupler. It's a relatively new printer, so I don't think that's in bad shape.