i have honda civic 2003 Vti prosmatic with cng installed. i got its full gas kit cleaned from a cng work shop. the problem now is its idle rpm on gas its not stable goes down and engine shuts down. Even during running sometime engine turn off. Mileage is 180k and changed oil also from 10w30 to 20w40 Havoline and the engine is eating up the oil day by day what to do need suggestions. Please help experts.