The first time I bought it did not attract my attention. When I loaded on the gas, the sound I heard from the engine is heard. Like the sound of the valve, but I don't know, maybe it is another sound. Also, during this full load, the vehicle suddenly knocks when it's at LPG. When I try to stop, it feels like kicking the gas suddenly and then the speed rises. When I press it slowly there is no problem when I say 2.. I told the service about this problem, it happens in every peugeot lipg. If you are using LPG, it will be tolerated, but I am sure this problem is something to be taken care of.