Hi Guys, I need advice.I want to equip my Corolla (GLi Automatic 2001) with CNG kit. Some CNG Conversion centers are saying it is essential to add Electronic Emulator & Elec. Spark Advance Control with Landi Renzo Kit & Cylinder. While others are it is not essential for this car with justification that these devices (Emulator & Advancer) are ways of making money. Please Advice.