Abstract: A dissimilar alloy type conditioner for conditioning liquid fuel in a motor vehicle is provided with shielding to protect the conditioner from electromagnetic interference which would render the conditioner ineffective. A conditioner is preferably covered with shrink tubing, wrapped with aluminum foil, a ground wire entrapped between any two layers of foil, and provided with a suitable cover. The ground wire is connected to a convenient grounded screw. Rubber tubing connects the conditioner on both inlet and outlet sides to a metal fuel line. The invention is practiced in combination with the conditioner or as a kit, as for retrofitted installation.