EJ257 4 cylinder turbo
"Some of the 2005 and later Subaru vehicle Engines (especially the turbo charged engines) are using CAN bus as their sole Vehicle/Vessel speed input channel. When those ABS Speed signal are removed, the ECU will force the Engine to run in limp home mode. This has posed some challenge for people who try to use the same automotive boxer and engines on Aerospace application, "
This seems like an issue.
Is running engines at the very low end of the power band causing excessive engine lugging and poor throttle response?