By Jody Campbell
Hypertech's Power Programmer - Power Made Easy
If you drive a modern 4x4 with a computer controlled engine, then adding a few extra ponies is a plug and play proposition. Hypertech has been building power adding computers for over 20 years, and when it comes to using 1's and 0's to do it, you can trust the computer geeks at Hypertech to unleash the power hidden in your engine.
We recently added a lift, gears, lockers, and larger wheels and tires to our 1999 Jeep Cherokee WJ. With the addition of larger wheels and tires and heavier suspension components, we could definitely feel the drag on the already underpowered 4.0 Liter I-6 under the hood. Some help was clearly needed and a quick call to Hypertech had a Power Programmer in our hands in no time.
With claimed gains of 15 h.p. and 24 lb/ft of torque available in a simple to install package, we were sold. Another big plus with the power programmer is the ability to diagnose and repair engine diagnostic trouble codes.
Installation:
Installation couldn't be easier, simply find the diagnostic port under the dash, plug the unit in and answer a few simple yes or no questions. The whole installation takes about 15 minutes. During the installation however, the programmer found two diagnostic trouble codes in our vehicle. The first was a charcoal canister vacuum leak, and the other, an out of range O2 sensor. We repaired both of them before we continued with the programming. Even with these two repairs, we were still done 
with the programming in less than an hour. The Power Programmer can be plugged back in at any time if you want to check for diagnostic problems or change power settings. Voila, you can now diagnose and repair your vehicle without the need to take it to the dealership.
Testing:
The first thing we noticed after installation was that the engine revved quicker and shifted much more firmly. While we didn't dyno the vehicle, we definitely felt the engine was quicker to rev and regained lost and untapped power. While we can't be sure if the vacuum leak and O2 sensor fault where causing any power loss, we can say that the engine definitely ran better and stronger after the programmer did its thing. Another big plus is the ability to return the vehicle back to all stock settings if you do need to take it to the dealer for warranty repair. The Power programmer also meets all CARB certifications by the California Green Nazi's, which means it meets or exceeds all emissions standards in your state as well. The one complaint we had about the programmer is that it doesn't allow for recalibration of the speedometer due to gearing changes and larger tires. When all is said and done, the Hypertech Power Programmer is a simple way to gain a few extra H.P. and as a bonus it is an invaluable tool to keep your computer controlled 4x4 in tip top shape.