i don't rember off hand what codes show up, but it all has to do with the VAM meter,
i got a brand new one
installed it...and am having the same problem,
car runs py, way rich, 1500 RPM idle, and sparatic at that.
i did the 88 t-coupe swap into my 89 mustang,
runs awsome (excpet the raw fuel smell) with out the vam meter, and the lack of passing emiisions
any ideas ?