Started with check engine light. And then the warning of 150 miles to limp mode. They said my pre-catalytic converter needs to be replaced. Only one problem they don't know when they will get the part and said there is 46 jeeps in the region parked waiting for the part. Don't know if its a supplier change....redo of the part. Really not a lot of information. Gave me a Dodge 200 as a loaner. No idea when I will get my Jeep Grand Cherokee Summitt back. I have 4 friends that have the Grand Cherokee Diesel. We are 2 for 4. The other guy went into limp mode and had to be towed.