Got Stuck! DEF one box for 2017 FreightLiner cascadia.

I'm at the dealership, have been here for 4 days, the dash board have shown engine, check engine and stop engine fault codes. The truck started to lose power. I pulled in the dealership back in Wednesday when the engine performance was limited to 55 mph. After that while waiting to be seen the stop engine fault cose came and it was limited to 5 mph. After the dealership did some testing and an overhead they stated today that the DEF one box needs to be replaced and costs 9000 $ i've had that truck for less than 3 months and I'm leasing to landstar, any advice on that issue as I'm thinking of letting the truck be repossessed.

 

I would do all I could to keep from having a repossession on my record. That messes up your credit for years. If you happen to be anywhere near Little Rock I could give you the name of a guy that would fix that truck for $2,500 and that would be the end of emission problems.

 

I'm having a feeling of getting scammed by the dealership! The thing is that's way too much, they said the DPF filter is brand new, it was replaced just before i got the truck but paying 9000 bucks is painful especially i barely started working with that truck, i have no idea what to do as they're the only dealership in town and the truck can't move any faster than 5 mph

 

Is $9000 installed?

 

How many miles/hours are on the truck? Was it equipped with APU prior to purchase?

 

I just did One-Box on my 2016 Cascadia. Plus injectors are the same time, that’s what caused the One-Box to fail.
About $23,000 job all together. Fortunately I have extended warranty so it was covered.

 

The part by itself they say it's 9000 but they said to wait till Monday to see if they can bring it down! The thing is i'm having a hard month already and I'm not sure if landstar will agree to loan me that money! On top of that i'm feeling like getting scammed and that replacing that one box is not neccessary

 

The truck has 612k miles on it at the moment, it's equipped with thermoking tripac apu

 

You don't want a repo on your record! But I understand your feelings of hopelessness.
After throwing 11grand at my emissions system in 10 months I had it " fixed" once and for all last spring ...you won't regret it and truck hasn't been in the shop since for anything emissions related ..
Have it towed if you have to , if you are near omaha I can point you in the right direction if you pm me .