It could be that the injectors for the misfiring cylinders are clogged, also i would check if the cables for those injectors are making a connection/the wires are in good shape. Here in Lithuania there are plenty of LPG service stations and the labor there is really cheap, i would probably just visit them. Also you wouldn't see any fault codes for the LPG system through OBD2, as the LPG system has a computer of it's own.

I would go also for the injectors (of LPG system) to be checked. Could be that not all of them are working properly, that's why the engine shakes so hard when running on LPG. Could be that you will have to replace them, as these type of injectors cannot be repaired, as for the piezoelectric one.

also called propane in the usa. sounds to me like your switch or switching valve is playing up.

Hello. Can you tell me what size container you use? I just bought a 9-5, I don't know what the maximum size is for the wheel.

Unless your filling it at wholesale prices(if you're in the business) it's an all around bad idea.

Its too cold! You have to have enough heat in the cooling system in order to vaporize the lpg. You can inrease the temp. in LPG control module