Cummins isx 15 CM2250 silent derate

[JimT]

(03-09-2020 )krowbar91 Wrote:  Thanks for the comments. DOC and DPF have been completely gutted. SCR has not been touched. Truck has operated for 25,000 miles with no problems until exhaust leak was fixed on DPF and PM was performed. I have also ran truck at operating temp, idled for 1 minute then driven truck on the road. Code still stays inactive and truck derated even after reset from insite. My question is being that system has been gutted does the turbo not recognize any back pressure which trips this code???? Took truck back to shop that did the original programming for delete and was advised that software and calibrations were good.

Like I said above, if the SCR can wasn't completely gutted then it's reflecting heat back toward the turbo AND it's slowly getting clogged up from soot and oil. The SCR can is filled with the same ceramic honeycomb as the DOC and DPF. Once the DPF is gone all the crap it used to catch now travels along until it hits the SCR media and slowly builds up there.

A super easy way to verify that a clogged SCR is the cause would be to disconnect the exhaust after the turbo and see if the code(s) disappear. The more you drive it like this the more likely you will cause serious damage to the turbo and the engine.

While you're not driving read up on the experiences of other unlucky people: The bad delete collection...