Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:1926351.
I couldn't find a decent 2 into 1 Y Splitter that uses PC4-M6 Couplers, so I knocked this up.
All you need is 3 PC4-M6 Pneumatic Couplers and 50mm of Bowden Tube to go from the coupler to the hot end.
#####Note: This does not work well with PLA. PETG and Copolymers work without issue
Update 1: reduced in size, tightened up holes for Pneumatic Couplers Update 2: Further reduction in size reduced filament path holes, refinement of Tool change script Update 3: Fixed error in model Update 4: Updated GCode - G4 is the key to get it working reliably
Tool Change Script - Simplify3D
G91; Relative Coordinates G1 Z+1 F420; Lift Z for Tool Change G1 X50 Y50 F4800; Move X Y for tool change G90; Absolute Coordinates T[old_tool]; Select Old Tool G92 E0; Zero Extruder G91; Relative Coordinates G1 E-5 F10000; Fast Retract 5mm G1 E2 F10000; Fast Reinsert 2mm G1 E-47 F10000; Fast Retract 47mm G4 P3000; Pause 3secs G1 E-60 F1000; Fast long retract G90; Absolute Coordinates G92 E0; Zero Extruder T[new_tool]; Select New tool G92 E0; Zero Extruder G91; Relative Coordinates G1 E105 F10000; Fast insert 105mm G1 E5 F300; 5mm/s Feed 5mm G92 E0; Zero Extruder G1 Z-1 F420; Return Z to resume printing G90; Absolute CoordinatesTool change Retraction in S3D is set to 6mm with a 2.5mm extra restart distance at 100mm/s