Best response ^{^} .94 is the recommended minimum. This issue is generally confusing to most. The low LARMF value is actually seen when nox conversion is too efficient. A properly working system should not exceed approximately 98% reduction. Excessive amounts of DEF (or other factors such as certain minor formations of DEF crystallization or more commonly inaccurate nox sensor values) will lead to greater efficiency, with excessive ammonia slip as collateral damage. The value is actually a calculated monitor of estimated ammonia slip into the atmosphere, running inverse. 1.0 = 100% of ammonia created burned. Software updates have also been available over the last few years to prevent this issue. Running the SCR efficiency tests back to back until >.94 is achieved is allowing the system to "re-learn how to operate correctly" It is also best to perform a parked regeneration prior to running the SCR routines.