88Mustang302

My car is running horrible. Its miss firing at idle and back firing through the intake while driving. When running KOEO I get code 34. KOER I get 34, 21, and 72. Code 34 seems to be a problem with the egr. And 21 is the ECT sensor out of range (prob needs to be replaced). But code 72 --No MAP change in "goose" test? Im not quite sure what that even means. Do I need to replace my map sensor as well. Any help would be great.

My car is a 88 mustang 5.0 and its still speed density.

Joel5.0

Suggest to rerun the KOER.... code 72 does not apply to '88 SD or MA systems. LUK