I have an '08 with a Magnaflow and in MDS mode it sounded like a helicpoter. Friggin annoying. I had Sluggish gas pedal and slow shift reaction because of it being in 4cyl mode all the time. I turned that crap off and holy crap. I'll never go back. Actually, I've never heard of anyone who tried turning the MDS off that has went to turning it back on. NOT YET! If you turn it off, I'm willing to bet, you'll never turn it back on!!!! Regardless of what you think right now.

 

Morepower29 you need to turn that thing on to extreem and just leave it alone. I've got one too and i'm on extreem for 9 months streight and my truck gets about 15.5 in the city and 19 on the highway at 75. The throtel by wire learns driving habits and with it turned up your not using as much throtel to move around. SO TURN THAT SOB ON AND ENJOY IT MAN!!!!!!

 

I do turn it on every now and then. I had it on last week when I had to tow my friends back hoe on his 20' equipment trailer about 17000lbs. Even when it is on my MDS is still on. I think all the sluggish feelings and no reaction time is in peoples heads. Yeah that's about what I get now. I get about 415-520 miles a tank (26gal). When you fill up 2 or 3 times a week premium fuel gets expensive.

 

thanks eveyone for the help.....guess its time to buy a programmer that turns MDS off..