Does anyone have a performance module or chip in thier XJ? Which brand/type works best? Is this worth doing?

 

Many discussion on this. Apparently our 4.0s dont get anything out of the chips. Best things to do are your intake, tb, exhaust n a few other things that i cant remember now.
Although its vague hope this helps

 

Chips are useless on the Jeep 4.0

 

Chips, tbs, and cai's are total junk and do next nothing if anything at all.. REGEARING is the most effective thing you can do.. After that addiing a supercharger or engine swap is it.. But even when doing those it's still best to regear to match your tire size..

REGEAR! REGEAR!! REGEAR!!!