Wehrli 100381 3.5 inch Passenger Cold Side Intercooler Pipe Kit | 2020-2025 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax L5P

Features:

• 3.5in high-flow cold side intercooler pipe
• Replaces restrictive factory plastic and rubber
• 14-gauge mandrel bent aluminum construction
• CNC flange with double O-ring seal
• Billet adapter with black anodized finish
• Includes silicone boot and T-bolt clamps
• Threaded bung for OEM temp sensor
• Improves boost pressure sealing and reliability
• Durable custom powder coat finish
• No tuning required, bolt-on install
• Fits stock trucks with no modifications
• Reduces risk of boost leaks and failures

Cold Side Intercooler Pipe Improves Efficiency and Durability

If you're looking to strengthen your Duramax’s charge system and eliminate one of its weak points, the Wehrli 3.5in Passenger Cold Side Intercooler Pipe Kit is a smart upgrade. The cold side pipe plays a key role in your truck’s performance—it carries cooled, pressurized air from the intercooler directly into the engine. That means any restriction, leak, or weakness in this part of the system directly affects throttle response, turbo efficiency, and overall power delivery. From the factory, GM equips the L5P with a combination of plastic and rubber components on the passenger-side cold pipe. It works well enough under light load, but when you start towing, tuning, or just pushing the truck harder, those materials can become a problem. Rubber can swell or degrade with heat, and the factory design is known to leak or blow out under higher boost pressure.

Heavy-Duty Construction with Direct-Fit Install

Wehrli’s upgraded pipe replaces that entire section with a one-piece, 3.5-inch mandrel-bent tube made from durable 14-gauge aluminum. The larger diameter improves airflow, and the smooth bends help maintain boost pressure all the way to the intake. On top of that, the kit includes a black anodized billet aluminum adapter with a CNC-machined flange and double O-ring seal at both ends. These connections are far more reliable than the OEM clip-style setup, giving you better sealing and peace of mind under load. The pipe also features a threaded bung, allowing you to reinstall the factory intake air temperature sensor without modification. It’s finished in your choice of Wehrli’s signature powder coat colors, adding a clean, high-end look to your engine bay while protecting the aluminum from corrosion and heat. Better yet, everything you need is included—high-quality silicone boots, stainless steel T-bolt clamps, O-rings, and all necessary hardware. Installation is straightforward and doesn’t require any tuning or other modifications. It bolts up to your stock truck using basic hand tools and immediately improves both reliability and performance.

Fits: 2020, 2021, 2022, 2023, 2024, 2025 GM 2500/3500HD 6.6L Duramax L5P

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