2003 ISX suggestions needed

[Hammerhead]

(07-23-2017 )DDlighttruck Wrote:  Why? Just because, or are they common sensors to fail? So four sensors in all you would recommend replacing?

Hi DD, welcome to the dark side...we will shine the light for ya...lol
An ECM is an Electronic Control Module, or "computer", and like any computer it's only as good as the information you give it, lie to it and put shi#t in, get shithouse lies out. Give it good information and it will have a good reliable output, that simple.
Sensors degrade over time, and after about 200k miles the degradation is enough that the improvements (fuel econ, power, etc.) from new sensors will easily recover the costs of the sensors.
I know you're from Ontario, so if you run south {shop name removed. no longer recommended} and shouldn't be too hard to get to for you. Your wasting your time going to Cummins. If you get out to AB, drop me a line and we'll meet up if I'm around.
As far as your driving style, around here we won't sugar coat it, if you drive hard and constantly want "more", expect to get blasted for it...
Wanting to "pass everything while going uphill" is fine when you're a brain dead company driver, but now that you own it and PAY for the REPAIRS, your new mantra is; I don't care if I'm the last one up the hill, as long as I'm the first one away from the fuel pumps and don't go to the shop for anything other than annual inspections! That's the key to success right there.