Canon CIS ink systems
Yes, using Epson cartridges. Did all the cleaning recommendations from site you listed and others as recommended by the forum members.
As I said, the black is working OK, but the yellow now is getting contaminated, like maybe there is a break internally between the black and yellow heads.
If I inject yellow ink directly into the yellow head port (thus like precharging) the yellow works fine. After this precharge is used up, the black finds its way back into the yellow head and the yellow is muddied up again.