computer reacting to mods

[jwhite]

Because I have been out of the Mustang seen for the last few years, excuse my stupidity. But I do have some questions regarding the 05 and up models. I have been told that with pretty much every mod, that the computer would have to be recalibrated. Is this true? If so, what mods can you get away with that will not affect the computer? I have an '05 GT that I just bought, and I plan on changing the exhaust very soon because it's too quiet. I plan on running an off road x-pipe, like I had on my previous cars. On those I had to put the MIL eliminator to stop the "check engine" light from coming on. Will I run into similar problems when I remove the stock converters?

[PureVenom]

I'm sure Mils will prevent the light from coming on, but i think putting the offroad on will cause the computer to go weird.

I know with a CAI it has been stated you need to get retuned. Cat back you should be fine...but the offroad I am not 100% sure of.

Maybe some of our 05+ guys will know for sure.

[hottcobra]

you will need to retune the ECM for the off road x-pipe. but be warned I put an off road x-pipe on my 06 GT and it sounded horrible not like the 04 & older. I guess it's cause the mufflers are behind the axle. I ended up putting the cats. back on and an x in place of the factory H

[PureVenom]

Quote: Originally Posted by hottcobra you will need to retune the ECM for the off road x-pipe. but be warned I put an off road x-pipe on my 06 GT and it sounded horrible not like the 04 & older. I guess it's cause the mufflers are behind the axle. I ended up putting the cats. back on and an x in place of the factory H

I'm not sure how stockish motors sound with the offroad...but they do sound good with long tubes, off road, and axel backs.

[hottcobra]

your right but I had stock manifolds and so does he

[jwhite]

Thanks for all of the input. I appreciate the feedback. I think I'll take the advice and just put an x in place of the stock h and leave the cats alone.