Hello,

I have the orange light coming on frequently with PO300 faulty code. The plugs have been changed but the engine runs still runs rough until it warms up/or changes over to gas. I have had a smoke test, changed the plugs, changed the MAF sensor, the throttle accelerator body and sensor. When warm the engine runs much better on petrol and perfect on gas. When running normally, it picks up as it should and runs without a problem. The coils have been checked (no problem), there are no intake leaks, I'm a bit more than confused, can anyone help please - Gordon

 

The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. Start by checking for intake leaks, intake gaskets are common caused of multi-cylinder misfiring. If the problem persist more tests needs to be done to diagnose problem. The other possible causes are: Faulty ignition, Clogged or faulty fuel injector, Intake air leak, Fuel injectors harness is open or shorted or circuit poor electrical connection, Ignition harness is open or shorted or circuit poor electrical connection, Insufficient cylinders compression, Incorrect fuel pressure.

 

Have you checked the valve clearances?
The gaps close more when the vehicle is run on LPG. The symptoms are more pronounced when the engine is cold - Missfiring, low on power, cutting out.
If you have done more than 50k miles on LPG, then it is worth getting the valve gaps reset.

Matt