bro
Check your switch petrol/cng.
Take it off from the jack ,and put the switch away. Take any wire or paper pin , The jack coming from inside of the console pull it a little .. there are some colored wires , put in the one end of the wire in red wire jack. the other end in yellow wire jack .. Your car will be on petrol .. check if evrything is normal ... then if it drives fine with this on petrol ... then ,,, take out the wire for a while let the fuel to be used ... then put one end in red the other in blue wire jack .. and the car will be on Gas ... IF this works then its a faulty switch .. change it ...
Chaoww