These glow plug deletes are used in conjunction with our turbo drain fitting. To use our low pressure turbo drain fitting you must remove the glow plug for cylinder 1 and install this to allow unobstructed oil flow for the drain. If you're worried about having starting issues, rest assured. We run cylinder 1 glow plug deletes on daily driven vehicles in some of the coldest climates in the country. As long as the other 7 glow plugs are functioning you won't have any issues.