If I had it to do over again, the order I would go in would be...

#1. Tuner. This will allow you to calibrate for all the other goodies, especially the tire size change...
#2. CAI or intake mods. You need to get the air IN before it can go OUT right?
#3. Exhaust. See #2.

Then again I'm no kid wanting loud pipes to wake the neighbors. I like good, power adding exhaust with a pleasant tone. But that is the least of my worries...

I don't get the issue with CAI and needing a custom tune though. Unless the MAF is being moved, or its data is somehow being corrupted, how is allowing more air to get to it going to make the truck run lean? The point of the MAF is to measure the air flowing through it right? That data in turn is used to calculate the amount of fuel sent through the injectors right? The computer *SHOULD* be smart enough to add bigger numbers without special programming... Is there something about a CAI that makes the MAF malfunction and send bad data?

 

Because the air to fuel table in your tune has a limited range. It can not blend the proper amount of fuel to go with the increased air volume. The custom tune redifines the parameters. The 2004s and 2005s came from the factory with a near lean tune. It does not take a lot of increased air to be too much.

 

So in other words, brain dead programming... Gotcha.

 

I know, I was more referring to the CAI.

 

No the issue is the fact that the MAF sensor is designed to read the data for the factory MAF tube size. Obviously any time you change the MAF tube size, the air passing over the MAF sensor is going to be changed by the velocity and flow. The MAF sensor has to be tuned for it to correctly read the air flowing through the MAF tube. The computer cannot make the needed changes because it simply is using the wrong size MAF tube, flow rates, etc to make processor changes. The MAF sensor and computer can easily make changes in air temperature, humidity, density, etc.

Late model Ford's, especially 2004+ F150s and 2005+ Mustangs have the most advance processors in the domestic auto industry by far. The computer can make a lot of changes but not this.

I hope this helps!

 

That is what I thought...

So for example, if you did the Gotts mod, with a K&N, the air / fuel tables should be unchanged. I had thought that as long as the other end of the equation is unchanged, then there should be no change in air / fuel ratio...

 

No, you can have excess air going past the MAF, not registered, p;us you can have the MAF reading the volume but the table for fuel may not go high enough for the air moving past. That is how I have understood Bill at PHP to explain it. Do a search on ASEmechanics posts, and see if you can find where he discusses it.

 

Jim, I think he's talking about the Gotts style intake with a drop-in filter. If so, he should be fine with this. The Gotts intake does not seem to provide too much air to exceed the limits of the A/F table in open loop. (And that's what Bill has told me, essentially, in several conversations about it.)

That's why I mentioned that a blower WOULD need a custom tune though, in another thread, since I'm certain it would exceed table limits.

- Jack

 

So if the MAF sensor is the problem, then why cant you buy an aftermarket MAF, by JET for intance, to solve the lean problem?

 

It's not an issue with the MAF sensor.. It's an issue with the computer and MAF sensor being tuned for a certain MAF sensor housing. Do not use anything but a stock MAF sensor unless you just want problems..

 

I agree about the Gotts except with 2004 and 2005s. I dont think ANY increase in volume is safe, but my statement was really responding to the last half of what he said. I was interrpreting his statement as saying the MAF would compensate for any amount of increased air flow.