Operation Section G420F Engine EMS (Engine management system) of G420F engine engine is an open loop LP system and/or closed loop gasoline system. 3-way catalytic muffler is not used for this system. LPG regulator and the mixer are operated in open loop as no mixture adjustments are made by the SECM. Manifold pressure from the TMAP, rpm from the crank position sensor and throttle position is used by the SECM to calculate load. Feedback from the electronic throttle is still provided to the SECM by the throttle position sensors (TPS). EMS schematic of G420F Dual Fuel engine 55