Originally Posted by salad

That's the thing. The Jeep 4.0L isn't a tuneable engine by those same standards. It's a tractor engine with roots in the 60s. It's already tweaked to the max and was discontinued because the factory couldn't tune it any further and still meet emissions standards.

If you want to make changes to the 4.0L computer you need to actually modify the engine first. Cams, stroke it, bore it, forced induction, etc. Stock parameters give no wiggle room except for high-flow exhaust and intake... and the still PCM does a great job of keeping things running.

Originally Posted by 96blackxj

i already have an intake that, i might get a high flow cat but i dont think that will help performance for cost effectiveness .. i want to get a header but theres soo many different ones and prices vary quite a bit i dont want a cheap piece either so im doing my research on those what works good..

with a cam idk about changing that, i dont think ill need all that done to it, but if i were to build a stroker motor or maybe decide to turbo it, how would i tune it?

Originally Posted by andrewmp6

I did a lot of digging what some stroker guys use is http://www.hescosc.com/products/7541...1#.UgXX6G2KyUk or http://www.hescosc.com/shop.asp?acti...1#.UgXXd22KyUk But they program it for you to match your jeeps specs.