I recently bought an 04 Mustang GT and had a couple of questions if any one has knowledge on the subject. I am going to put on a cat back exhaust and a K&N cold air intake. Will I need to do anything to modify the air/fuel ratio or is that controled by the computer. And if so will I need to change the chip to make it run right or is it controled by the computer via sensor that will automatically adjust the air/fuel mix to keep it running properly?

 

Modern computers in automobiles have 'long term' and 'short term' memory. What you should do after you make the change is get your computer cleared out (anyone with a shop that has the ability to read the codes from the computer can do this.) This will benefit you in that the car will only be using information based on the current configurations. Also be aware the first four on/off cycles after you reset the computers memory are going to make the most change, so be sure and get it fully up to operating temp all four times and try and give the computer some variety, high rpm, low rpm, some freeway driving, some city with stoplights etc.

 

Beginning in 1989 the Mustangs came with a "mass air" fuel injection system. There is a meter inbetween the air cleaner and the throttle body that directly measures the air going into the motor. This allows the fuel injection to easily adapt to performance parts: intake, exhaust, cam, heads, ect. The more stuff you put on your Mustang, the more air it will pull through the meter. The meter reads the extra volume of air, and adds more fuel accordingly. I see no reason to clear the codes. All you need to do is install the parts and enjoy your pony. By the way...I've owned 4 Mustangs...(2) '67 coupes, my current '87 5.0, and my wife's '01 V6. Nice to see we have common interests [img]i/expressions/face-icon-small-happy.gif[/img]

 

If you don't clear the codes, then your computer will be using the information from back when it didn't have the mods to calculate what it has now - as well as the current data, but it does indeed use the old data which is why clearing it is good. If you are changing a lot of stuff, it is a good idea, and there is no down side. If it is difficult to get it done then wait till you get your next oil change done and you should be fine.

 

lightweight is right, you shouldnt have to touch a thing. i have an 88 mustang with a vortec supercharger and had to convert to mass air and upgrade fuel pump/injectors etc,but your cars computer will not have any problems with those mods you mentioned, enjoy your car!

 

yes your car will run fine with those mods.........but listen to Blackhawk b/c I have heard the same thing from shops, your computer does know the difference even if your butt doesn't.

 

i have an 04 GT too and i also have a flowmaster dual exhaust and a K&N cold air intake system. i didn't do anything with the computer and the car runs great! i checked into running the chip on the car and i was told that doing it would only give me a minimal amount of HP but is not necessary. BTW your gonna love it when your done i was so amazed by the power it added and it sounds like a freakin beast[img]i/expressions/face-icon-small-wink.gif[/img] the only problem is that i waste so much gas cuz i drive it like i'm qualifying[img]i/expressions/face-icon-small-happy.gif[/img]

 

Clearing the computer is not required but probably wouldn't hurt anything. As far as clearing the computer you can simply disconnect the batter terminals for a few minutes and the computer will clear. At least that is the case on GM computers. Not sure about Furd.

 

want some real power? pm me, i am an ATI PROCHARGER dealer.

 

i wanted a super charger for the stang but me and my boyfriend are buying a 69 rs camaro and saving up to fix that beast up[img]i/expressions/face-icon-small-wink.gif[/img]