with 26k it might have been changed already or never had a problem because it was actually driven. I didn't have any issues with mine but put a ford lighting pump anyways. Usually around 80 bucks on ebay and you can pick up the plug for like $10. Some over on mbworld just posted the part number for the plug. I got a used plug from a ford mechanic, he had it lying around. Unless your opting for the bigger intercooler not sure the johnson pump will make a difference.