Mar 1, 2012 #1 M Mayhem New member Joined Mar 1, 2012 Messages 1 Reaction score 0 Location WV Hi I have a 2000 XJ with a 4.0 and I wanted to know if anyone has used a performance chip on theirs and if they actually work by increasing H.P. and M.P.G's? Also what brand? Thanks
Hi I have a 2000 XJ with a 4.0 and I wanted to know if anyone has used a performance chip on theirs and if they actually work by increasing H.P. and M.P.G's? Also what brand? Thanks
Apr 20, 2017 #2 G goliver9 New member Joined Feb 15, 2017 Messages 13 Reaction score 0 Jet performance chip is a good brand. You can see slight hp improvement.
