It is possible to DPF delete without removing DPF (Diesel Particulate Filter), after all. But this comes with its own concerns. In this post, you will find out an expert’s position on this topic. This topic has been discussed often as stealth DPF delete without a tuner on various platforms, including vehicle community forums.
DPF Delete Without Removing DPF
So, can you delete DPF without removing the filter? Yes, you can, but this comes with concerns. Removing the DPF filter or drilling a hole in it may eliminate the exhaust back pressure, thus preventing the truck from deciding it needs a regeneration (regen). Could this mean the truck will not need a tuner to turn off the regens or any warning lights?
Well, drilling through the DPF without a tuner or SIM’s would cause the ECM to note the lack of back pressure. As a result, it will trigger the Check Engine Light (CEL) and put the truck in limp mode.
You might be able to fool the pressure sensors without a tuner or SIM. The solution is to add resistors to the ends of the plugs to bypass the sensors, but a tuner would be needed otherwise.
Some people use a stealth method with a tuner. Simulators were typically a solution before tuners were available. There is also some debate over the resistance value, with both 110 and 330 ohms.
Do note that a “stealth” DPF would replace the pipe. You would want to be code-free without a tuner, so you will need 330 ohm sims and a pressure sim. Also, the EGR should remain plugged in and installed.
You might be fortunate, though, to pass emissions testing with a gutted DPF and NOx converter after stealth delete. Also, you can get DPF and NOx cans without the internals, which are hollowed out; they tend to work well for visual inspections.
Will Your Truck Enter Regen?
You might have been under the impression that one could not remove the DPF without a tune. However, on your way home, you decided to return your truck to stock settings. Surprisingly, the truck runs exceptionally well even with the DPF delete, showing more power than the stock setting and without any Check Engine Light (CEL) warnings. But is there any reason the truck could not be left in this state, and would there be any signs of tuning if you updated their truck with the latest flash from the manufacturer?
Well, the truck would eventually go into regeneration mode. The best thing to do is load a stock tune (“Stock No Regen Tune”) that turns off the regeneration function when a DPF delete is installed. Usually, after a certain number of miles, the truck would go into regeneration as a backup system if the pressure sensor malfunctions.
Some people gut their DPF two months before getting tunes for their truck. However, the experience is that the truck will go into regeneration and may never come out.
Pressure or distance, typically at around the 675-mile interval, can cause regeneration.
Warning: You do not want to remove and gut the DPF. Your truck might go into permanent regeneration after doing so, and you may have to wait for two months for tunes to address the issue.
What About Dealer Warranty?
Some dealers would only void the warranty on the exhaust system if the DPF is removed, but the rest of the powertrain may remain under warranty. Usually, dealers are strictly against using a tuner. If you are looking for a way to prevent the check engine light from coming on and to stop the regeneration process, a tuner is important. Regeneration is a process where excess soot in the DPF is burned off.
Removing the DPF without a tuner could lead to engine damage due to the engine trying to regenerate even if the DPF is not present. This could result in fuel being dumped into the exhaust, which could have detrimental effects on the engine.
As mentioned earlier, you can always trick the sensors into thinking the DPF is always clean. Unfortunately, this would not necessarily stop the regeneration process. The Engine Control Module (ECM) might still call for a regeneration based on mileage and other factors. All in all, if you are concerned about the warranty, do not DPF delete.
Should You DPF Delete Without Removing DPF?
You might think of rerouting the 9th injector fuel to return to the tank or blocking it off and then installing a hollowed-out filter pipe. But how would the computer detect such a change?
In theory, it might work. However, once the DPF is removed and the sensors are unplugged, it could cause the vehicle to go into limp mode, so you will need to tune it.
In my experience, simply dummying out the stock exhaust may not work. You will then have to wait for weeks or months for tuning. It is often a waste of time and effort when you could just delete the DPF and be done with it.
Conclusion – DPF Delete Without Removing DPF
Regular cleaning cycles are important for the DPF. If these high-heat cleaning cycles are not performed, the DPF will soon become clogged with particulates. In essence, the DPF will clog without cleaning.
Note also that the SCR system, which uses DEF and NOx sensors, is separate from the DPF system. The DPF system uses a regeneration process to burn out accumulated soot particles. Deactivating the regeneration system but keeping the DPF in place would be harmful.
Ultimately, the practicality of DPF delete without removing DPF depends on your location and mechanical skills.
Read also: 23 DPF Delete Pros and Cons