i had the same prob with my liana,i bought the car like 8 months back,first few months i had no issue's, the car is 58,000km done, missing on cng and rpm dropping etc, took it to the company and yes they had a complete checkup and recomended me the 25k coils!!, but tell you wht,which will amaze you, i took the car to a local mechanic and he reconsealed its plug wires!!! he took RS 400 , and its been over two months the car runs great! though the original plug wires cost RS,2500 , have its plug wire checked i recommend!