[granite]

HAS ANYONE HAD/HAVE THIS PROBLEM
So, I've been there done that. After the 5th trip to the dealer , and after all the TSB software and hardware upgrades DONE, it had been agreed upon the CAT replacement was in order. So the wait wasn't terrible and 10 days later all was complete.
Some good miles later I'm still dealing with a new issue/problem, that is, from when the CAT was replaced my mileage has dropped from what used to be 27-28 to now 22 mpg. Same diesel station, same DEF, same driving habits. Just last week it came to me, maybe the diesel quality degraded so I changed to another high volume diesel station but still seeing no increase in mpg. Hate the thought of visiting the dealer because who knows what will be my next issue after they tinker.

 

[Casper2]

I have had my cat replaced....... but it's been snow followed by more snow. I have not driven on enough pavement since to say one way or another. I am assuming it takes a little extra fuel to keep the cabin warm when the outside temp is in the single digits.

 

[ericlakin]

This link provides some detail on reduced MPG while using the winter diesel blend. It is old, but it may still be applicable to those of us in snowy states:

http://www.dieselplace.com/forum/76...01987-winter-diesel-cetane-decreased-mpg.html

 

[Casper2]

Clear roads today so I reset my avg mpg meter and drove to and from work..... 6 degrees going 12 coming home. A 36 mile round trip...... not highway not city...... 28.4 Avg. The same as last summer, or close enough...... So I'm gonna say that for me the new cat has not reduced mpg.

 

[Mpgtow]

Clear roads today so I reset my avg mpg meter and drove to and from work..... 6 degrees going 12 coming home. A 36 mile round trip...... not highway not city...... 28.4 Avg. The same as last summer, or close enough...... So I'm gonna say that for me the new cat has not reduced mpg.

I have also experienced reduced mileage after the cat replacement..... But been running the engine a lot to warm it up before getting in. It's been crazy cold.
Hopefully this issue will be resolved like your situation

 

[granite]

My situation has NOT been resolved and that's what troubles me. I'm hoping too that these cold temps are the cause of diminished fuel economy but, that remains to be seen.

 

[Casper2]

I'm not "resolved" as of yet........ I went for an inspection in early January and because of the old cat it failed..... which I knew it would but was no problem because I get 60 days on emission problems here in Mass. After the cat was replace I put 720 miles on it with no CEL's to make sure all codes were clear. When I had it reinspected it failed again. So I still have my "R" sticker. Tuesday I'm going to the dealer for an Inspection by them and see what happens. Should have gone there to begin with... but didn't see this one coming. Also as far as the mileage is concerned I have a 2WD. I special ordered it that way. Your AWD might take more to move in the cold.

 

[Casper2]

I went to the dealer and this is the result........ the error code for the cat will not reset because of the weather. It has been to cold and it needs to get to 50 or above in order for it to clear. They wen't through this with one other vehicle about 2 weeks ago. So I get a waiver request from Chrysler and get my sticker. Apparently this is unique to the diesel and is considered a problem that needs to be addressed. Maybe Al Gore designed this thing.... and he figured what with global warming and all it wouldn't be a problem. It was -14 last night and now at 2:30 pm it is 8 degrees outside. The way things are going it is unlikely the code will clear before mid April.

 

[granite]

What the dealer should have done was cranked up the heat in the garage and parked it in there for a long night. I don't believe the garage in the dealership drops below 50 degrees at night. At that point he would have to have some other explanation.

 

[Casper2]

I had assumed that the vehicle would need to be moving and perhaps go through a regen.... I asked if this effected vehicles other than diesel and he said no. I suppose it could be a line but it would be one that he has to now get Chrysler and the state of Mass to back him up on.

 

[eaglescout1987]

I sure hope this is nonsense. I've been waiting nearly 3 months to get my new Cat installed and if that doesn't solve the MIL because it's not above 50 degrees, I may lose it. Of course it could also be because they put the wrong oil in the engine twice without my knowledge....

 

[Mpgtow]

HAS ANYONE HAD/HAVE THIS PROBLEM
So, I've been there done that. After the 5th trip to the dealer , and after all the TSB software and hardware upgrades DONE, it had been agreed upon the CAT replacement was in order. So the wait wasn't terrible and 10 days later all was complete.
Some good miles later I'm still dealing with a new issue/problem, that is, from when the CAT was replaced my mileage has dropped from what used to be 27-28 to now 22 mpg. Same diesel station, same DEF, same driving habits. Just last week it came to me, maybe the diesel quality degraded so I changed to another high volume diesel station but still seeing no increase in mpg. Hate the thought of visiting the dealer because who knows what will be my next issue after they tinker.

Well, I'm concerned as stated earlier, that same is occurring.. 21-22 mpg. Also was at 25-26 prior to the cat being replaced. What gives?

3 days later Update- filled up tank with diesel, coincidently its 40 degrees today. Tracked mileage and today it's back to 26-27 mpg.
Not sure... Is it the cold to lessen the mpg so drastically or did I have poor fuel in the tank?