We researched and compared the most popular upgrades for the L5P Duramax engine, analyzing manufacturer specifications, industry standards, and aggregated owner feedback from forums and reviews. Our goal is to help you choose upgrades that deliver real performance gains without compromising reliability. Below are our top picks, each evaluated for performance, durability, value, ease of installation, and safety.
| Photo | Product | Score | Buy |
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Edge Products CTS3 Insight Monitor Best Overall Monitor/Tuner Combo 5-inch color touchscreen, up to 60+ PIDs, includes EGT/boost sensors |
9.0 | 🛒 Check Price |
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S&B Filters Cold Air Intake Best Cold Air Intake Dry or oiled filter option, 2-piece housing, fits 2017-2023 L5P Duramax |
8.7 | 🛒 Check Price |
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BD Diesel Exhaust Manifold Best Upgrade for Reliability Cast iron construction, direct fit, includes gaskets and hardware |
8.4 | 🛒 Check Price |
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AFE Power Bladerunner Turbo Inlet Pipe Best Bolt-On Power Mandrel-bent 4-inch aluminum, includes silicone couplers and clamps |
8.1 | 🛒 Check Price |
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Mishimoto Transmission Cooler Best for Towing All-aluminum, 1-inch thick core, includes AN fittings and lines |
7.8 | 🛒 Check Price |
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MBRP XP Series Exhaust Best Sound Upgrade 3-inch aluminized steel, muffler delete option, single or dual exit |
7.5 | 🛒 Check Price |
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L5P Duramax EGR Delete Kit Best for Maximum Performance (Off-Road Use Only) Includes EGR block-off plate, gaskets, and hardware; requires tuning |
7.2 | 🛒 Check Price |
1. Edge Products CTS3 Insight Monitor: Best Overall Monitor/Tuner Combo
We researched the Edge CTS3 Insight Monitor and found it to be the most comprehensive monitoring solution for L5P Duramax owners. Based on manufacturer specs, it reads over 60 engine parameters including EGT, boost, and DEF level, and displays them on a crisp 5-inch touchscreen. Owner feedback highlights its easy plug-and-play installation via the OBD-II port and the ability to log data for troubleshooting. However, the tuning capability requires the separate Edge Evolution CTS3 module, which adds to the overall cost.
This monitor is ideal for owners who want to keep a close eye on engine vitals, especially when towing or running other performance mods. If you don’t need monitoring and just want a simple tune, you might skip this and go for a dedicated tuner. Also, the screen can be a bit bright for nighttime driving without dimming adjustments.
- Real-time monitoring of EGT, boost, DEF level, and transmission temp
- Custom tuning via Edge Evolution CTS3 (sold separately) for up to 120 hp gain
- Easy plug-and-play installation with OBD-II port
Pros: Large, bright display readable in sunlight; Extensive data logging capabilities; Supports multiple vehicle profiles
Cons: Tuning module is an additional purchase
2. S&B Filters Cold Air Intake: Best Cold Air Intake
We compared the S&B Filters Cold Air Intake against other popular options like AFE and K&N. Based on owner feedback and the spec sheets, the S&B offers a superior sealed housing that draws air from the fender, reducing intake temperatures. The dry filter option is a plus for those who want to avoid oil contamination. Performance gains are modest but consistent, especially when paired with a tune.
However, we found that the oiled filter version requires careful maintenance to avoid MAF sensor issues. Some owners reported needing to clean the MAF after installation. This intake is best for owners who want a reliable, low-maintenance upgrade without extreme gains. If you’re chasing maximum horsepower, a more aggressive intake might be better, but the S&B is a solid all-rounder.
- Up to 15% more airflow than stock, as per manufacturer
- Sealed housing prevents hot engine air from entering intake
- Clear lid allows visual filter inspection without removal
Pros: Easy installation with basic hand tools; Reusable filter saves money long-term; Noticeable turbo whistle sound
Cons: Oiled filter can over-oil MAF sensor if not careful
3. BD Diesel Exhaust Manifold: Best Upgrade for Reliability
We researched the BD Diesel Exhaust Manifold as a solution to the common factory manifold cracking issue on L5P Duramax engines. Based on owner feedback and industry standards, this cast iron manifold is significantly stronger and less prone to thermal stress. The improved flow also helps reduce exhaust gas temperatures, which is beneficial for towing or tuned trucks. However, installation is not a weekend job; it requires removing the turbo and several other components.
This upgrade is best for owners who have experienced manifold cracks or plan to run high power levels. If you have a stock truck and don’t push it hard, you may not need this. Also, the cost is higher than some other upgrades, but for reliability-focused owners, it’s a worthwhile investment.
- Replaces weak factory manifold prone to cracking
- Improved flow for better turbo spool and EGT reduction
- Made in USA from high-nickel cast iron
Pros: Addresses a known L5P weak point; Superior durability over stock; Bolts on with no modifications needed
Cons: Installation is labor-intensive (requires removing turbo)
4. AFE Power Bladerunner Turbo Inlet Pipe: Best Bolt-On Power
We compared the AFE Bladerunner Turbo Inlet Pipe to the stock plastic elbow and found that it reduces airflow restriction. Based on owner feedback, the gains are most noticeable when combined with a cold air intake and exhaust. The aluminum pipe is well-made and includes quality silicone couplers. Installation is straightforward, making it a good entry-level upgrade.
However, on a completely stock truck, the power gains are minimal (maybe 5-8 hp). Some owners reported that the pipe didn’t align perfectly with their aftermarket intakes, requiring slight adjustment. This upgrade is best for those already planning other mods or wanting a slight improvement in spool time. If you’re expecting a dramatic power increase, you’ll be disappointed.
- Smoother airflow than restrictive stock elbow
- Up to 8 hp and 15 lb-ft torque gain (manufacturer claim)
- Direct fit with no tuning required
Pros: Noticeable throttle response improvement; Easy 30-minute install; Durable aluminum construction
Cons: Minor gains on stock trucks; best with other mods
5. Mishimoto Transmission Cooler: Best for Towing
We researched the Mishimoto Transmission Cooler for L5P Duramax trucks used for heavy towing. Based on aggregated owner feedback from towing forums, this cooler effectively lowers transmission temperatures, which is critical for long climbs or hot weather. The all-aluminum core is durable and the kit includes AN fittings for a secure connection. However, installation requires removing the front grille and some disassembly, which may be challenging for beginners.
This upgrade is best for owners who regularly tow heavy trailers or drive in mountainous terrain. If you don’t tow or drive hard, the stock cooler is likely sufficient. Also, the price is higher than some other coolers, but the quality justifies it for serious towers.
- Doubles transmission fluid capacity over stock cooler
- Reduces transmission temps by up to 30 degrees F (owner reports)
- Direct fit with no cutting required
Pros: Significantly improves towing reliability; High-quality construction with AN fittings; Complete kit with everything needed
Cons: Installation is time-consuming (2-4 hours)
6. MBRP XP Series Exhaust: Best Sound Upgrade
We compared the MBRP XP Series Exhaust to other brands like Flowmaster and Magnaflow. Based on owner feedback, the MBRP provides a deep tone without excessive cab drone, especially with the resonator option. The aluminized steel construction is durable but not as corrosion-resistant as stainless steel. Installation is straightforward, though some owners reported alignment issues with the tailpipe.
This exhaust is best for owners who want a more aggressive sound and modest performance gains. However, if you live in an area with strict noise ordinances or prefer a quiet cabin, consider a muffled version or a different brand. Also, the aluminized steel may rust over time in salty climates, so stainless steel might be a better long-term choice.
- Deep, aggressive diesel sound without drone
- Mandrel-bent tubing for max flow
- Easy bolt-on installation with factory hangers
Pros: Noticeable horsepower and torque gains (5-10 hp); Lighter than stock exhaust; Lifetime warranty
Cons: May be too loud for some (especially with muffler delete)
7. L5P Duramax EGR Delete Kit: Best for Maximum Performance (Off-Road Use Only)
We researched the EGR Delete Kit for L5P Duramax and found that it effectively removes the exhaust gas recirculation system, which is a common source of carbon buildup and high EGTs. Based on owner feedback from off-road and competition users, this mod can improve engine reliability and power when combined with a proper tune. However, installation is complex and requires mechanical skill, and it is illegal for street use in many jurisdictions.
This upgrade is only recommended for off-road or race-only vehicles. If you drive on public roads, skip this due to legal and warranty concerns. Also, without proper tuning, the engine will run poorly and trigger fault codes. We advise consulting local laws before considering this modification.
- Eliminates EGR system for cleaner intake and lower EGTs
- Requires custom tuning to disable EGR and avoid check engine light
- Off-road use only; illegal for street use in most states
Pros: Significant reduction in intake carbon buildup; Lowers EGTs and improves engine longevity
Cons: Illegal for on-road use; may void warranty
Frequently Asked Questions
What is the best first upgrade for an L5P Duramax?
Based on owner feedback and our research, the best first upgrade is a cold air intake like the S&B Filters. It’s easy to install, provides a noticeable improvement in throttle response and turbo sound, and sets a foundation for future mods. Many owners also recommend a monitor like the Edge CTS3 to track engine vitals before adding power.
Do L5P Duramax upgrades void the warranty?
Some upgrades, especially those that alter engine tuning or emissions systems, can void the factory warranty. Bolt-on parts like intakes and exhausts are generally safe if they don’t cause damage, but we recommend checking with your dealer. EGR deletes and tuners will almost certainly void the warranty. Always consider the warranty implications before modifying.
How much horsepower can I gain from L5P upgrades?
Gains vary by combination. A cold air intake and exhaust might add 10-15 hp combined. A tuner can add 50-120 hp depending on the tune level. The biggest gains come from a full package: intake, exhaust, tuner, and possibly an EGR delete (off-road). Realistic peak gains are around 150 hp with a safe tune and supporting mods.
Are L5P Duramax upgrades easy to install?
Most bolt-on upgrades like intakes, exhausts, and inlet pipes are beginner-friendly and can be installed in an hour or two with basic tools. More complex mods like transmission coolers, manifolds, and EGR deletes require mechanical experience and may take several hours. We recommend professional installation for advanced upgrades.
What is the best exhaust for L5P Duramax sound?
Based on owner feedback, the MBRP XP Series offers a deep, aggressive tone without excessive drone. For a louder sound, choose the muffler delete option. If you prefer a quieter exhaust, consider Magnaflow or a resonated system. Ultimately, sound preference is subjective, so we recommend listening to clips online before purchasing.
Our Verdict
After researching and comparing the best upgrades for the L5P Duramax, our top pick is the Edge Products CTS3 Insight Monitor for its versatility as both a monitor and tuner platform. For a close runner-up, the S&B Filters Cold Air Intake offers excellent value and easy installation with consistent performance gains. Choose based on your goals: monitoring, towing, sound, or maximum power.
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