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2020 Silverado 3500HD Duramax/Allison, LT, Crew Cab, SRW, Std. Bed, Z71, 4WD,
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Just spit ballin' here, but since emission deletes are probably now a thing of the past, has anybody tried leaving all the emission hardware in place, and installed an exhaust cut-out ahead of the DPF? Some exhaust would still flow through the factory system, including through all the various sensors, but backpressure would be reduced, and regenerations would decrease, as would EGR and DEF consumption. In a sense, it would "fool" the ECM into thinking the engine was just producing less CO, NOx, soot, so less after-treatment was needed, but it might not trigger a CEL. Any thoughts or experience?
 

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I may be wrong but I think the sensors register levels within a certain parameter. If a hole is cut into the pipe that would introduce oxygen and reduce the levels and the sensors would register a fault code
 

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Just spit ballin' here, but since emission deletes are probably now a thing of the past, has anybody tried leaving all the emission hardware in place, and installed an exhaust cut-out ahead of the DPF? Some exhaust would still flow through the factory system, including through all the various sensors, but backpressure would be reduced, and regenerations would decrease, as would EGR and DEF consumption. In a sense, it would "fool" the ECM into thinking the engine was just producing less CO, NOx, soot, so less after-treatment was needed, but it might not trigger a CEL. Any thoughts or experience?
Interesting. I’ve been thinking myself about how to make the emissions more reliable, given my low-mileage driving habits.

There is no exhaust flow measurement per se, but the ECM might infer flow from engine RPM, fuel delivery, MAF, and other parameters. If the DEF and/or 9th injector dosing is based on that (which I think is likely as a feedforward mechanism since the NOx sensors probably have a somewhat slow response), you might still have problems.

Also, I’m reading that the 2020+ models do regens based on some internal algorithm long before the DPF gets anywhere near 100% soot loading (differential pressure). If the ECM is running a lot of inferential/algorithmic stuff for things like this you may really have a challenge on your hands.

As for other options, I wonder if a couple of large (even parallel) cats would reduce NOx a decent amount while being much more reliable and lower maintenance than the DEF system. Particulates I’m not sure one could do much about with alternate means that are accessible to the owner, beyond tuning (though I think if you are not rolling coal, this is much less an issue than NOx).
 

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How Regeneration Should Occur

The DPF traps the soot generated as a part of the normal operation of a diesel engine so that it is not sent into the environment. The process of regeneration enables the vehicle to clean the filter so it can trap more soot. Factors that determine when the ECM will try to perform a regeneration include:

After approximately 36 gallons (136 L) of fuel used since the last regeneration.
A maximum distance of 800 miles (1287 km) have been traveled since the last regeneration.
A pre-determined number of engine hours since the last regeneration.
A calculated or measured soot mass of 100% in the particulate filter.

When any of the above criteria are met, the ECM will perform a regeneration as soon as all the correct conditions are met. If the ECM cannot perform a regeneration, the ECM will only look at the soot mass to determine to display the Continue Driving DIC message or to set DTC P2463.
 

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Particulate matter is collected, then regeneration vaporizes it. The process reduces "particulate matter" to vapor.
 
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When you say "vaporize", are you meaning that it reduces the size of the particulate? This would make the "vaporized" particulate not as noticeable in the exhaust, but more easily spread into the environment.
 

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Funny
I was thinking about a cut out also.i was gonna have it cut out when the pedal went more than 75%.that's when I see the soot mass get added on quickly.


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Just spit ballin' here, but since emission deletes are probably now a thing of the past, has anybody tried leaving all the emission hardware in place, and installed an exhaust cut-out ahead of the DPF? Some exhaust would still flow through the factory system, including through all the various sensors, but backpressure would be reduced, and regenerations would decrease, as would EGR and DEF consumption. In a sense, it would "fool" the ECM into thinking the engine was just producing less CO, NOx, soot, so less after-treatment was needed, but it might not trigger a CEL. Any thoughts or experience?
For one issue- the exhaust gas temp in front of the DPF (after the cat on the back of the turbo) is gonna be red hot during regen (9th injector sending in fuel) and you will need somewhere/way to vent that extremely hot gas without setting anything on fire. The next issue might arise when the ECM does it's tests to determine EGR flow ( by opening EGR, comparisons to Mass Air flow etc).
Have you looked to see if it's physically possible to fit said bypass into the space you have?
 
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