Sztem így jobb:
#include <a_samp>
public OnFilterScriptInit()   return print(\" *|Epsilon Nitrous|*\"),1;
new bool: PlayerNitro[MAX_PLAYERS];
public OnPlayerKeyStateChange(playerid, newkeys, oldkeys)
{
if( newkeys == 1 || newkeys == 9 || newkeys == 33  || newkeys & KEY_FIRE)
{
    if(GetPlayerState(playerid) != PLAYER_STATE_DRIVER || !CheckNitro(GetPlayerVehicleID(playerid))) return false;
   if(!PlayerNitro[playerid])
   {
      AddVehicleComponent(GetPlayerVehicleID(playerid), 1010);
      PlayerNitro[playerid] = true;
   }
   else
   {
       RemoveVehicleComponent(GetPlayerVehicleID(playerid), 1010);
       PlayerNitro[playerid] = false;
   }
}
return 1;
}
public OnPlayerExitVehicle(playerid,vehicleid) if(PlayerNitro[playerid]) OnPlayerKeyStateChange(playerid,  KEY_FIRE,128);
stock CheckNitro(vid)
{
    new NoNitro[] = { 522,481,441,468,448,446,513,521,510,430,520,476,463 }; // unknown
for(new e = 0; e < sizeof(NoNitro); e++) if(GetVehicleModel(vid) == NoNitro[e]) return false;
return true;
}