I was speaking to a local dealer for AFE, K&N, etc...he sounded like he knew what he was talking about, but then again I'm not really sure because everything he told me contradicts what I have read in this forum.

I was asking him about replacing the CAI and how easy it was to do...he said it was a piece of cake as long as I bought the one for my make and model. I then asked him what kind of tuner I should think about getting...he looked at me strange and asked why I would want to do that. I explained that I read quite a bit about how when you swap out your factory one with an after market one it is higly recomended that you get a custom tune done and that most people agree they wouldn't replace the CAI without having it done. He told me that was false because when you replace the CAI you have to unplug the battery and when you plug the battery back in, the computer will reprogram itself and adjust accordingly.

Can anyone confirm that this is true? This guy claims he's done it on a few of his trucks over the years without ever doing a custom tune and in each instance he's improved his gas mileage by over 3 MPG and has noticed a big increase in performance.

Any thoughts?

 

No it's not true. What motor do you have? If you've got the 5.4 3V, it's important to get the custom tunes. The MAF sensors are able to make minor adjustments for elevation changes but not a completely different intake system.

 

I have the 5.4, not sure what 3V is though? I know it's a V8. I kind of thought what this guy was saying was weird, especially since it was the complete opposite of what I've read here, but not knowing anything about this, I figured I'd ask.

 

the '04 and newer 5.4 is a 3v, so you do have it. I did tons of reading up on it too. unfortunately, it was right after i had installed my intake. Lots of people say that the 04s were guaranteed to run lean. some of the '05 and up are able to correct and others aren't. its luck of the draw. only way to know is to bring your truck to a dyno and have them find out what your a/f is. SAFEST bet is to just get the custom tunes anyway. seems like it adds much more HP, TQ, and better gas mileage anyway!

 

The 3V means the heads have 3 valves per cylinder. It's always the best idea to get custom tuning when adding modifications like air intake, etc.

 

How can it be called a "custom tune", when there's no real time air/fuel data logging involved, whether on the dyno, or with wide band O2 sensors, and wide band data logger/software? Where's the "custom" in these custom tunes?

 

A custom "mail order" tune is far different than a dyno tune. The tuner takes in account the current mods of the vehicle as well as elevation, driving conditions, etc to create a custom tune. Customers can data log if they would like and email the data logs to the custom tuner, in most cases, and the tuner will tweak the tune if it needs it. More than likely, if it's a reputable tuner like Justin, Bill, or Mike they will not need any tweaking as they've all done a ton of these vehicles.

 

Do the '04+ 4.6's have this lean problem?

 

no. only the 04+ 5.4 3v. they re-designed the maf sensor on the 3v's, so when you put it in a new intake, it will be a little off.

also, the 3v 4.6's also can run lean, but currently, they are only offered on mustangs.

 

Cool...thanks for the reply Sharpshooter