:gr_patrio Okay, we have lots of posts, but no one seems to know for sure whether the mass sensor on our '04-05 hemi Durango's limits the effect of these 3 components. The 300 hemi C folks are positive about the jetchip, but they have the disabling feature for their engine, and possibly have different engine control computer. What about our Durango hemi's? The same for magnaflow and/or hiflo cats with the Durango exhausts. Has anyone done dyno tests or had before/after quarter mile e.t.'s and mph's of hemi Durango's w :gr_patrio ith Gtech or dragstrip testing? I want to invest in more h.p., torque and gas mileage (when pushing lightly on the skinny pedal), but no one on this forum seems to have a definitive answer. :huh: I am not complaining about anyone at all, but surely someone has tried these components-one, two or all 3-and has some Objective evidence of whether the mass sensor disables our efforts. :help: PLEASE, someone, if you KNOW for sure, please post your evidence and firsthand knowledge of the results, or lack of results. Thanks to you all. I do enjoy this board and have learned a lot from it. Now I'm ready to spend money, so I need definitive evidence if someone has it. Thanks again. Flyntgr :gr_patrio