The main thing you will notice with the JET chip is smoother and quicker shifting. It will give you a little boost in performance but the biggest advantage is the better shifting. If you listen to what JET recommends for the Stage II chip you will want to have Intake, Exhaust and run 91 octane or higher gas. I have Intake and Exhaust and I run 93 octane gas.
If you want to get the JET chip get it from AutoAnything ... They have the best price around. That is where I got mine from.
http://www.autoanything.com/performance ... 55056.aspx
A Scan Gauge II is a good tool to have for clearing codes and reading data. I can tell you that will all the mods I have, I have NOT thrown any check engine lights. I also had thrown an Intake Sensor light because of my mistake but other then that, NO lights!
Any exhaust you do will for the most part have to be custom made. I'm not sure (i could be wrong because I haven't check in a long time) that anyone makes a bolt on kit for our truck yet. I when to a local muffler shop and bought a Magnaflow muffler and had them custom fab a cat-back system. The longer the muffler the quieter it will be, also the less performance you will get out of it. Any muffler shop can recommend a good muffler based on what you want out of it.
An exhaust system will open up the exhaust flow and give a boost in power and gas mileage. A good Intake and Exhaust combo can help with gas mileage and give a little boost in performance.
** DISCLAIMER ... Don't expect to break any land speed records with your Liberty. It is VERY slow to begin with. YES you can get a little more out of it but it's limited. Depending on factory options like skid plates and tow package your truck could be even slower right out of the gate. A base model Liberty with just about NOTHING on it runs about a 10 sec 0-60. Mine as an example which has full skid plates, full tow package, leather powered seats, 18" upgraded rims + all my mods runs about 9 sec 0-60. As you can see weight will slow it down even more then it already is. [/list]
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Out - 2008 Jeep Liberty Limited 4x4
In - 2011 Jeep Liberty Carbon Edition
http://www.cardomain.com/ride/3972889/2 ... ed-edition