Anyone know where to get a new glow plug besides the dealer?  Even the dealer does not stock and very expensive to order with no assurance of how long .  Mine is a 2021 Jeep Gladiator,  love the truck but after only 43000 miles I get the check engine light with a #4 glow plug code set. Are these glow plugs the same as some older engines, or is there a substitute?  None of my local or on line parts suppliers  can get them.   Help!    Thanks