AFAIK, closed loop came std on greentop saffs ( due to the introduction of cats), BT and ST Escorts. Worked fine on std engine/management, but due to lack of knowledge/skill/ 99% of aftermarket chips simply binned the feature as it was not needed to make power, hence a lot of people still think anything bigger than greens cause borewash, and you have to run a tuned cossie at 8% CO ...

and again, AFAIK, stu can run closed loop on 1000cc injectors and still get it to almost an MOT pass on emissions WITHOUT a cat , the main things that cause the closed loop not to work is huge ports in the head and lairy cams, belive ( and someone correct me if I am wrong) that closed loop is unavaliable on cams bigger than BD10's? Still a great mod though Also, the closed loop can only "trim" the fuelling within a certain percentage of it's base figure, so say the injector duration is 0.30 millisecs, the closed loop system can only alter this by 15% either side of that figure, so any big mods and the ECU won't be able to move the injector duration far enough to compensate for big changes....