Upgrade your 2020 L5P Duramax

Emissions Friendly Upgrades for the 2020 Duramax

There is no denying how well GM has executed these latest generation heavy duty trucks. The 2020+ Silverado and Sierra has been a total success in the market and that L5P Duramax paired with the all-new 10-speed Allison transmission is just flat out impressive. While this truck was a real showstopper in the show room outfitted with the top of the line Denali package with its massive chrome grille, factory 20” wheels, and enough cameras to see virtually everything in a 360-degree radius around the truck, of course it couldn’t be left stock for long.

In the first part of this project, we added a nice roll-up Lorado tonneau cover from AgriCover, a DPF-back exhaust system from MBRP and a high flow intake tube and turbo inlet pipe from Wehrli Fabrication. We followed up those modifications with a 2” leveling kit from ReadyLift, 34” Toyo Open Country A/T’s and some unique gloss black milled 20” Rogue wheels from our Anthem Off-Road. With the truck finally looking the part, it’s time to get back under the hood for some added performance. You may think that Duramax packs enough punch to do everything you need it to, while we can somewhat agree, it’s hard to not mention that laggy pedal feeling GM programmed into the truck. Besides, if you knew how simple it was to add another 130+ horsepower with power adjustability on the fly, we know you’d ask us how. So, we’ll just tell you and save everyone the time of having to talk about.


In 2017, GM took some major steps on the electronics and programming side of things in the L5P Duramax and made it virtually impossible to install aftermarket tuning. Of course, with time, the aftermarket found their way into that locked ECM, but this has meant possibly losing your warranty and your kids college fund as the early tuning options were rather expensive. Edge Products is not a new name in the diesel tuning game and has been known as a leader in the market for more than 20 years now. Through years of experience, their extremely knowledgeable engineering and calibrations teams developed the Pulsar for L5P, a tuning device unlike anything else on the market.

With the intake and exhaust upgrades already taken care of, this 2020 was ready for some extra power and feature control with the help of a tuning device. The Pulsar CTS3 Insight kit from Edge Products was exactly what we were after.
The Pulsar is a unique computer module that piggybacks directly on to the factory Engine Control Module (ECM) that is located down in the driver wheel well area right behind the radiator and headlight. Access is gained by removing the inside fender liner.

While the competition spent it’s time trying to crack into the ECM and flash tune it like it’s been done for years, the team at Edge Products engineered a stand-alone computer module that simply plugs into the factory ECM to interpret the signals being sent from the ECM to the engine. The all-new, redesigned, Pulsar V3 adjusts four major signals to get more power out of that Duramax safely. By modifying signals like injection pulse width, injection timing, fuel rail pressure, and airflow the Pulsar has the ability to add power and torque without modifying the ECM in anyway. This means the truck can be returned completely back to stock, with no tuning traces for the dealer to see, by simply removing the Pulsar from the truck.

After removing a handful of small torx bit screws, the fender liner could be tucked out of the way giving perfect access to the trucks computer that will be removed from the truck all together. The instructions Edge includes offers simple to follow steps, including disconnecting the large wiring harness connectors.
The Pulsar module for L5P is like nothing else on the market for the late model Duramax, as it basically plugs into the factory computer and modifies the signals it sends to the engine. This allows the factory ECM to remain completely stock, so no programming, no flashing, no unlocking, so returning the truck completely back to stock is as simple as just removing the Pulsar unit.

The state-of-the-art device offers smooth integration into your truck with shift-on-the-fly power levels and feature control using your steering wheel controls. Pulsar offers the ability to adjust your top speed limiter, tire size and gear ratio adjustments (all industry exclusives) along with manual DPF regeneration, transmission relearns, and reading/clearing Diagnostic Trouble Codes. Also programmed into the Pulsar are safety features like transmission slip backdown and EGT backdown.

The Pulsar unit will plug directly into the factory connectors on the ECM. You’ll need to take care during this step to make sure everything is lined up properly and pressed down squarely and firmly so that the small pin connectors are make a solid connection and are seated.
Edge Products includes some small brackets and bolts to securely hold the Pulsar unit onto the factory ECM. The engineering team at Edge has done an incredible job thinking through this whole process and making it as straight forward and robust as possible.
With the Pulsar installed onto the factory ECM, it can now be placed back into the truck. While some of the factory mounting hardware will be re-used, the kit also includes a couple new mounting tab brackets and bolts to make installation and access a little easier.

To make Pulsar and the user experience even better, Edge offers even more control when their popular Insight CTS3 is added into the mix. With Pulsar and Insight working together, you get added control over your throttle pedal sensitivity (no need for an extra throttle booster device), High-Idle settings, cold engine protection, and a built-in turbo timer. The Insight monitor obviously gives you extra gauge displays for watching all your engine vitals but gives you the ability to fine tune your Pulsar settings specific to your driving preferences. The package really integrates nicely as one cohesive unit and makes for the ultimate driving and towing experience. And did we mention Edge’s dyno proven 135hp and 291ft-lbs of torque over stock on Level 5? You thought your L5P ran well stock, you’ll be completely amazed by how well it’ll handle a load or the unsuspecting Camaro in the lane next to you.


With the power and performance added to this Duramax, we also wanted to investigate better fuel filtration. One simple and effective upgrade for the fuel system is to convert the factory fuel filter setup over to the popular 1R-0750 Caterpillar spin-on style filter. Of course, converting from the expensive internal style factory filter to an old school spin-on will require an adapter of some kind, which is where Extreme Filter Housings comes in. There machined adapter piece makes this conversion super simple and straight forward.

Once the ECM and TCM were reinstalled and securely mounted to the truck, the three large wiring harness connectors can be plugged back in. They’ll only go one way, you’ll just want to be sure the keepers all line up and the latch mechanism can rotate smoothly and latch with the safety lock.
At this point, the Pulsar is installed, and you could fire the truck up and enjoy all the added power and feature control using your steering wheel control buttons. But to unlock some extra features within the Pulsar and add some monitoring in the cab, the CTS3 Insight is an excellent upgrade to go with it.
Adding the CTS3 Insight to Pulsar for L5P Duramax offers complete adjustability above and beyond what is available by Pulsar on its own. With the CTS3, you can now adjust power back down settings and even throttle pedal sensitivity, so you can fine tune the driving experience to best fit your driving style and needs.
While the Pulsar is pre-calibrated with throttle response adjustments within the tune to take away that dead pedal feel, with the Insight, you can set that response in each individual tune to your liking. Prefer the less aggressive pedal feel while towing but want it snappy and quick in level five? No problem, that adjustment right there at your fingertips.

Factory replacement fuel filters can run as much as $60, when the CAT fuel filters can be had for about $20, so not only will the EFH kit offer some cost savings over the life of the truck, the CAT filter offers better protection and is easier to replace when it’s service time. The factory fuel filter bowl is made from plastic, and is notorious for stripping, making filter changes a nightmare. The EFH system will allow you to rid yourself of those troubles forever and offer remarkably simple spin-on filter change, just like you’re doing your oil. The added filtration will also aid in reliability, longevity, and performance of your fuel system and engine.


While we haven’t been able to get this truck on the chassis dyno just yet to test our power gains at the tires, the initial test drive was really all the proof needed to feel the immediate and substantial gains offered by the Pulsar V3 unit. The power comes in smoothly and carries all the way through the RPM range. We’ve found that daily driving on Level 3 offers the best of both worlds with a little extra pep stop light to stop light without being too much to handle. The factory 10-speed transmission took a few days of driving to adapt to the new power, but this combination has turned out to be quite impressive for towing. The adjustable pedal response and added low end torque just makes the truck move more effortlessly, which is hard to believe knowing how well this 2020 Duramax performs in stock form. In our next part to the project, we’ll be looking into some more airflow upgrades and adding some bling under the hood.

The backdown settings for Pullsar can also be adjusted to ensure you’re getting the most out of your truck, without causing any undo stress or harm. Power can remain stock until the engine is up to full operating temps and the Pulsar can turn itself down if needed based of your EGT thresholds.
Another great feature within the Pulsar CTS3 kit is the ability to setup a turbo timer to delay engine shut off after the key has been removed. Setting this up to your preference, either EGT or time based, the engine will remain idling until it’s cooled off and allowed the hot oil to circulate out of the turbocharger.
Tire size adjustment is a feature not offered by any other plug and play performance device on the market for L5P Duramax, making Pulsar an even better value. If you’ve added larger tires to your truck, your speedometer most likely reads faster than it should, and with Pulsar, you can recalibrate the speedometer to keep the highway patrol from paying you a visit.
We’ve done stories on the Edge Insight CTS3 before, so we won’t go in to too much detail here, but after more than a year on the market, Edge continues to add more and more support and coverage for Insight. It really is the most versatile and easiest to use monitoring device on the market.
While we focused mostly on performance this go round, we also wanted to do something about engine longevity and filtration. The fuel filter conversion kit from Extreme Filter Housings was developed specific for the 2017+ Duramax application and offers superior filtration over the factory filter, and it’s cheaper to replace to boot.
The machined billet adapter makes it super simple to replace the expensive factory filter with a spin on style filter from Caterpillar. These filters have an excellent reputation in diesel applications as they offer excellent flow and filtration down to 2-microns. The EFH kit makes future services less expensive, and quicker to change.
Sitting on the bench you can see the difference between the EFH kit and the factory internal element style filter. The installation couldn’t be easier, as you just thread the adapter onto the factory housing under the truck, then thread your filter into the adapter. That’s it.
Fuel filter swap completed in less than 15 minutes with next to no mess on the floor. The added filtration should make for a happier injection pump and injectors. It’s all in the name of added performance and longevity.


Edge Products

Extreme Filter Housings


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