Im running some ebay found injectors with my zetec. It idals with a 12.5 afr any think leaner than that it hunts at times or hesitates when pulling away. Light throttle loads low 14's in most places up to 7 psi the afrs hang around the 13afr mark but any think over that they richen up to 11.8/12.0 then any think higher than 20psi 11.7 all tho my injectors are flat out now and im changing all my inlet/exhaust so new injectors will be coming next