In laymen terms your Jeep is as smart as a bag of nails. The on board computer inside your Jeep is programmed for the most tame of drivers. The Jet chip, which is actually an inline module which plugs in between your computer and its wiring harness, takes your computer back to school. It does this by adjusting shift points to better optimize the added power which you have just recieved. It adjusts your fuel/air ratio and fuel curve for better performance. Your ignition timing is adjusted as well as all electronic goveners removed. EXPECT more power in all 4.0, 5.2 and 5.9 engines. This is a very easy upgrade as it only takes 10 minutes to install. Prices are widely ranged from $275.00-$450.00 Canadian.You will be very pleased with the way your Jeep performs.Please notice there are 2 different Jet chips for your Jeep. The first is called Stage 1 and is not recommended as the increase in power is not very noticable. The stage 2 chip is what most dealers will sell now, but just make sure. I marked the coolant resevoir mounting bolts because it needs to be shoved to the side to install the chip.
I installed the stage 2 module(chip)(myself)6 months after purchasing my 1993 JGC 4.0. It took 30 minutes. On paper the 4.0 has a 14 horsepower increase and noticable smoother shifts. The V-8 has almost a 21 horsepower increase and the same smoother shifting.I liked the increase in power as the more responsive and non-lagging engine kept up with my driving habits. There's a smile on my face when the bone-stock 5.2 V-8 starts falling to my side at about 30 km/h and falls faster as the rpm's hit 4500. This also considering that my JGC gets about the same mileage as my father's 1995 2.5 YJ that's stock. (He's taking measurements to compensate for this). I purchased the chip in Canada from "Unit 9 19257 Enterprise Way Surrey British Columbia (1-604-534-4366) for an excellent 340.00 Canadian + TAX. This should answer some questions.