Just got my o4 gt w/an automatic a new K&N cai and and a borla stinger catback system installed. after i got those in i had a code showing, was able to fix that by just unhooking the battery for a few mintes. Anyway my gas mileage has taken a freagan hard hit and it just doesnt seem to "act" right once in a while powerwise.

I have my set of 4.10s ordered and in the mail and i know ill need a tune after those go in, but it will be a few weeks before i got enough time off work to tear into the gears. do i need a tune now to fix the current mods or can i run it for a few weeks with those problems and not blow it up or some other costly problem?

 

On the GT, yes its generally a good idea to get a tune for any aftermarket CAI for 99+

 

why is a tune needed on a 2004 gt with cai? the cai are basically the same as the stock intake

 

Well its not "needed" per say. Just recommended, as with any upgrade that increases are flow.

 

tune is not needed but you should do it! get those gears in and whatever else you wanna mod then take it to the dyno!! itll become a whole new beast

 

You should be fine until the gears go in. My first 2 mods were a CAI and cat back. I ran it that way for a while before getting a tune. Although, i didn't have any gas mileage or performance problems either.

 

Have you changed the FUEL FILTER yet?

It should be done every 30K and yes, if not down (over time) you'll lose mpgs.

http://www.americanmuscle.com/ford-fuelfilter-9804.html

 

It wouldn't hurt to tune it. Personally, I would tune it if it were my car. That's just me

 

What are you going to do for a tune? Are you going to get a handheld tuner, or go to a dyno? Are you going to be doing any other mods in the near future? If you get a hand tuner from some place like American Muscle you can get free tunes for future upgrades so you might as well get the tuner now. Also it will correct your speedometer for the 4.10s. If you are done with mods and just going to a dyno to have the car tuned you should wait a couple weeks and get the gears in so you only have to pay to have it done once.

 

its pointless to tune it ( untill you get the gears in) because the cold air intake isnt changing anything, they do pretty much nothing for 2v's, with the catback and intake you probably gained 5rwhp. they are worth it for looks and sound though!