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I have a 2005 GT and I recently just put a new engine in my car last week. I have BBK longtube headers and BBK shorty x-pipes. I heard that if I put in this exhaust set up with out getting my car dyno tuned that it will screw up my car. I literally just replaced my engine with a brand new ford built 4.6 and I don't want to put this exhaust set up in and have it ruin stuff, is a tune required. If so how much do custom tunes usually cost. Thanks for your time
 

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By chance do you already have a tune of any sort?

The computer on the 2005+ cars is really sensitive to mods that increase airflow (like CAI's and headers), those can cause the engine to run lean and throw codes. You'll probably also need a tune to turn off the rear O2 sensors.

A tuner with unlimited tunes from AM is $380.

Hope that helps.
 

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So I do need a tune for this, and no I currently don't have any tunes on my car. And would it be better if I just take my car down to a dyno shop and buy their custom tune rather than buy one from AM then take it to the dyno?
 

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Ok, here is how it works, hopefully this won't be too confusing. You can buy a handheld tuner by diablosport, sct, etc. that holds your custom tunes. You can buy internet tunes from several sources and they can be very good. I have had a couple from a couple sources and they were good. Some of these guys can dial it in pretty good because they have dyno tested a mustang with your mods on a dyno before. You can also go to a reputable speed shop and have it custom tuned with their program but it can be extremely expensive. The best shop near me has a program I have never heard of and they want over 800 bux to tune it (no thanks). You also have to take it to the shop if you get another mod. If you do not plan to run cats be careful in Cali they are the most strict and you will have to find a way to pass emissions as well. They will look for everything out there. You will need a tune with that set up for sure, it will run but you don't want to long and at the very least you will get the o2 codes popping up. Hope this helps.
 

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So to clarify, you have to have a handheld tuner of some sort regardless (which plugs into the diagnostic port right under the dash on the driver's side). SCT is generally one of the favorites but there are others out there.
 

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Correct, I only know of one program at a speed shop near me that may not require a hand held tuner but I could be even wrong about that. Your best bet is to get a tuner in my opinion.
 

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I have a 2005 GT and I recently just put a new engine in my car last week. I have BBK longtube headers and BBK shorty x-pipes. I heard that if I put in this exhaust set up with out getting my car dyno tuned that it will screw up my car. I literally just replaced my engine with a brand new ford built 4.6 and I don't want to put this exhaust set up in and have it ruin stuff, is a tune required. If so how much do custom tunes usually cost. Thanks for your time
Hey Go,

Great question!

Whenever you add longtubes or delete the cats, it is highly recommended to tune the car!

I would go with the Bama X4/SF4 Power Flash Tuner as you will not only recieve the tuner, you will also be enrolled in the free tunes for life program.

Not to mention, the Bama V2 tunes are out of this world!

Check out this video:




Hope this helps and let me know if you have any questions!

-Will
 

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Many vendors like AM usually do a Package Deal, where you buy the Handheld Tuner (Diablosport or SCT) and a specific tune all in one deal. Local shops that do Dyno tunes can do the same deal. In most cases the Tuner runs between $300-$400 and then the dyno tune can run up to $100 an hour. Some of the best tuners can tune a car in as little as an hour, getting timing and A/F mixture just right. If it looks like you do need a new tune, and the addition of headers is usually a good sign you do, shop around, see who has the best deal for you.
 

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Discussion Starter #9
So what would happen if I installed the LT headers and x pipe without a tune, how long could I run it like that without a tune? And what would bad about it
 

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Whenever you mess with any of the electronic sensors that feed information to the computer, you have to "tune" or "calibrate" for that, to correct the information that is being sent to the computer, or the computer may control things wrong (because it is going on bad information).

In the case of long tube headers and X-pipe, that usually implies that you have deleted the catalytic converters; and also the rear O2 (oxygen) sensors. I'm pretty sure the rear O2 sensors are only there to confirm that the catalytic converters are working; or they might help fine tune the air/fuel mix, I am not sure. But in any case, if they are removed, then the computer will be looking for the signal that it is supposed to get from them, and it won't get it, so it will at least throw a code and it might throw off the air/fuel mix.

In this case, the "tune" simply tells the computer "forget about the rear O2 sensors, you don't need them any more" (which I'm pretty sure is no problem, unless you need to pass emissions inspection, because the emissions tester will check to see that the O2 sensors are working, and if they are turned off, you fail)

So -- hopefully someone else can confirm about the rear O2 sensors and air/fuel mix -- but I'm pretty sure the engine will be OK, but you will have a "check engine" light on the dash, if you delete the cats without a tune.

If your new X-pipe has catalytic converters, then I'm pretty sure the tune is needed to calibrate for the signal from the new O2 sensors which is probably slightly different from the original O2 sensors. But again I'm pretty sure it is not a big deal, since they are only checking for the cats working correctly.
 

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Discussion Starter #11
Whenever you mess with any of the electronic sensors that feed information to the computer, you have to "tune" or "calibrate" for that, to correct the information that is being sent to the computer, or the computer may control things wrong (because it is going on bad information).

In the case of long tube headers and X-pipe, that usually implies that you have deleted the catalytic converters; and also the rear O2 (oxygen) sensors. I'm pretty sure the rear O2 sensors are only there to confirm that the catalytic converters are working; or they might help fine tune the air/fuel mix, I am not sure. But in any case, if they are removed, then the computer will be looking for the signal that it is supposed to get from them, and it won't get it, so it will at least throw a code and it might throw off the air/fuel mix.

In this case, the "tune" simply tells the computer "forget about the rear O2 sensors, you don't need them any more" (which I'm pretty sure is no problem, unless you need to pass emissions inspection, because the emissions tester will check to see that the O2 sensors are working, and if they are turned off, you fail)

So -- hopefully someone else can confirm about the rear O2 sensors and air/fuel mix -- but I'm pretty sure the engine will be OK, but you will have a "check engine" light on the dash, if you delete the cats without a tune.

If your new X-pipe has catalytic converters, then I'm pretty sure the tune is needed to calibrate for the signal from the new O2 sensors which is probably slightly different from the original O2 sensors. But again I'm pretty sure it is not a big deal, since they are only checking for the cats working correctly.
yeah im only gonna run it without a tune till i can afford to buy one which would only be about 1 month
 

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There are some other threads on here that talk about how the O2 sensors work, to make sure that the rear O2's do not affect the air/fuel mix, you could try some searches ; or maybe someone else who knows for sure will chime in.
 
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