SKU #: PSI-12300 MPN #: 12300

PSI Power Performance Tuner 98-03 Cummins ISB 5.9L Medium Duty Engine

Name: PSI Power Performance Tuner 98-03 Cummins ISB 5.9L Medium Duty Engine
Brand: PSI Power
Price: 795.0 USD
Availability: InStock

$795.00

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PSI Power Performance Tuner 98-03 Cummins 5.9L Medium Duty engine

Description

Give your medium-duty 5.9L Cummins the added power and responsiveness it needs with the PSI Power Performance Module. Designed for 1998–2003 Cummins engines equipped with the Bosch VP44 injection pump, this module delivers up to 30% more horsepower and torque while offering the potential for improved fuel economy. Whether you're pulling a heavy trailer, climbing grades in a motorhome, or working your truck under load, the additional performance helps the engine respond more effectively when you need it. An adjustable three-position switch lets you select between stock, 15% increased power, and up to 30% increased power, giving you control over how much performance you want. The PSI 12300 uses load-based electronic signal optimization rather than rewriting or flashing the factory ECM. Its plug-and-play wiring connections integrate with the factory engine harness without requiring cutting, splicing, or permanent wiring modifications. The included mechanical switch allows you to change power settings, while the module works with the factory engine management system to adjust engine performance.

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Give your medium-duty 5.9L Cummins the added power and responsiveness it needs with the PSI Power Performance Module. Designed for 1998–2003 Cummins engines equipped with the Bosch VP44 injection pump, this module delivers up to 30% more horsepower and torque while offering the potential for improved fuel economy. Whether you're pulling a heavy trailer, climbing grades in a motorhome, or working your truck under load, the additional performance helps the engine respond more effectively when you need it. An adjustable three-position switch lets you select between stock, 15% increased power, and up to 30% increased power, giving you control over how much performance you want.

The PSI 12300 uses load-based electronic signal optimization rather than rewriting or flashing the factory ECM. Its plug-and-play wiring connections integrate with the factory engine harness without requiring cutting, splicing, or permanent wiring modifications. The included mechanical switch allows you to change power settings, while the module works with the factory engine management system to adjust engine performance.

NOT LEGAL FOR SALE OR USE IN CALIFORNIA

Vehicle Fitment

1998-2003 Cummins 5.9L Medium Duty Engine With Bosch VP Fuel Pump

WARNING: Cancer & Reproductive Harm - P65Warnings.ca.gov

FEATURES & BENEFITS:

Enhanced Power & Torque: Experience a noticeable boost in horsepower and torque to handle heavy-duty tasks with ease.
Improved Fuel Efficiency: Reduce fuel consumption while maintaining performance, helping you save at the pump.
Plug-and-Play Installation: Easy-to-install design with no special tools or modifications required—get back on the road faster.
Safe & Reliable: Works seamlessly with factory settings to ensure long-term durability and emissions compliance.
Adjustable Power Settings: Use the included mechanical switch to select the power setting of your choice.
Warranty Friendly: Leaves no trace on the ECM!

About PSI Power

PSI Power Products develop performance electronics and engine management solutions for diesel trucks. Their Truck Edition lineup includes performance modules and tuners engineered for a wide range of work trucks, vocational vehicles, RVs, and Class 8 semi-trucks, helping operators improve horsepower, torque, throttle response, and overall engine efficiency. With application-specific solutions for popular diesel platforms from manufacturers such as Cummins, Caterpillar, Detroit Diesel, International, and other major engine brands, PSI Power products are designed to deliver practical performance improvements for vehicles that spend their time hauling, towing, and working in demanding conditions. Featuring straightforward plug-and-play installation and products engineered, tested, and built in the USA, PSI Power provides dependable performance upgrades for commercial fleets, owner-operators, and diesel enthusiasts looking to get more capability and efficiency from their heavy-duty equipment.