The breather that comes with the kit may not be ideal for injected engines, the tank pressurises during use to a very high level. As it is only a one way valve it only let air in as you use up fuel. The other issue we’ve been having is when there’s a slosh of fuel it lets out a waft of petrol which really is not very pleasant.
Out solution was to get a mocal two way valve and a positive shut off so air can get in and out. Additional when there’s a slosh it doesn’t leak petrol all over the place.
Fitted the mocal valve today brimmed the tank and went for a long drive – no more petrol small wafting through the car when accelerating hard or going up a hill!