lkreykes

Northern Michigan.

Hi all. I recently completed swapping a 1999 Legacy wagon EJ223 into a 2000 Legacy wagon EJ251. Runs drives stops steers. But the idle bounces up and down really bad...have tried new IACs and cleaning it, didn't help, I put the ECM from the 99 into the 00 and it idled beautifully. ButStalled as soon as I put it in gear and seemed to have been in limp mode. Put the 00 ECM back in, idles up and down but runs just fine. Any ideas on what isn't communicating between the 2 model years? Cheers