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JET Performance 58705S JET Stage 2 Computer Chips/Modules

JET Performance 58705S JET Stage 2 Computer Chips/Modules

$138.50
$138.50
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The JET Performance 58705S JET Stage 2 Computer Chips/Modules from JET Performance is a Stage 2 ECU upgrade designed for vehicles with performance modifications like aftermarket exhaust, intake systems, and headers. This performance chip builds on the Stage 1 calibration with more aggressive fuel and timing maps that take advantage of increased airflow. It's the right choice for enthusiasts who have upgraded their engine's breathing and want the ECU to match. This unit is JET part number 58705.

Expect gains of 20-30 HP depending on your vehicle's modifications and engine platform. The Stage 2 tune is optimized for engines running aftermarket intakes and exhausts, with recalibrated fuel and ignition maps throughout the RPM range. Transmission tuning improves shift quality and timing for a more connected driving feel.

Installation follows the same process as the Stage 1 — either EPROM replacement inside the ECU or plug-in module installation depending on your vehicle. JET includes vehicle-specific instructions and any required hardware. The Stage 2 calibration is permanent to the chip or module, but you can return to stock by reinstalling your factory chip. JET recommends Stage 2 for vehicles with at least an aftermarket intake and exhaust.

JET Performance has been tuning vehicles since the 1980s, and this Stage 2 chip/module continues that legacy. Add JET Performance 58705S JET Stage 2 Computer Chips/Modules to your build and enjoy professional-grade ECU calibration without a custom dyno session.
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Frequently Asked Questions

How much horsepower will this JET Stage 2 computer module add to my vehicle?

The JET Performance 58705S JET Stage 2 Computer Chips/Modul typically delivers 25 to 45 horsepower and 30 to 50 lb-ft of torque for a noticeable seat-of-the-pants performance improvement. JET Stage 2 tuning is more aggressive than Stage 1 and requires the use of 91 octane or higher premium fuel to support the advanced timing and fuel maps. These substantial gains make this an ideal upgrade for enthusiasts who want maximum safe performance from their daily driver.

How long does it take to install this JET Stage 2 computer module at home?

Installing the JET Performance 58705S JET Stage 2 Computer Chips/Modul takes between 20 and 40 minutes depending on whether it is a module-style or chip-style unit for your application. Module versions plug directly into your vehicle's diagnostic link connector or engine sensor harness with no tools whatsoever required for the job. Chip versions require accessing the ECU and swapping the PROM, but detailed instructions and wiring diagrams are included with every unit.

Will this JET Stage 2 computer module leave any trace on my ECU or warranty?

The JET Performance 58705S JET Stage 2 Computer Chips/Modul leaves no permanent modifications on your vehicle and can be returned to completely stock configuration in just minutes. Module-style Stage 2 units simply unplug from the harness, while chip versions require reinstalling the original factory PROM into the ECU. JET specifically designs these calibrations to be invisible during routine dealer diagnostic scans so you can service your vehicle with confidence.

Does this JET Stage 2 computer module work with both gas and diesel engines?

The JET Performance 58705S JET Stage 2 Computer Chips/Modul is available for both gas and diesel engines, but each uses completely separate and distinct calibration strategies. Gas Stage 2 tuning requires 91 octane or higher fuel and focuses on timing advance and fuel curve optimization for maximum horsepower. Diesel tuning optimizes injection timing and turbo boost parameters for improved low-end torque, so confirm your engine type before ordering to ensure correct calibration.

How does fuel economy change with this JET Stage 2 computer module versus stock?

Fuel economy with the JET Performance 58705S JET Stage 2 Computer Chips/Modul varies because Stage 2 tuning is designed to prioritize maximum performance over fuel efficiency. Some drivers are able to maintain stock MPG figures during conservative cruising due to optimized part-throttle calibrations. However, the aggressive timing and fueling maps will decrease fuel economy under heavy throttle use, which is the trade-off for gaining 25 to 45 additional horsepower.

Will this JET Stage 2 computer module work well on a stock vehicle or need mods?

The JET Performance 58705S JET Stage 2 Computer Chips/Modul works well on stock vehicles but truly shines when paired with supporting modifications like cold air intakes and cat-back exhaust systems. JET strongly recommends using 91 octane or higher premium fuel to prevent engine knock and maintain optimal ignition timing advance. Stage 2 is best suited for enthusiasts who want maximum safe horsepower and torque from their daily driven vehicle.