Hi all new to the forum. I've been lurking and trying to read up on some things. I've gotten the 3.5 AirForce One, and have an xcal2. My buddy tuned it. He has been tunning now for about 5-6 years, but for some reason my truck is still pulling codes P0171, P0174. He is confused about what to do. He said he richened it up for me. When doing normal driving it doesn't throw a CEL, but when I go WOT it does. What could he do to fix this. I guess this is geared to Troyer or any other tuner. I'm not asking for any trade secrets just looking for something that would keep my truck from going lean. He was looking into a MAF XFER or something for my intake, this is greek to me. I have know idea what he is talking about. If any help could be give I would greatly appreciate it.

Brack

Oh I have a 2005 F150 supercrew. 5.4 with dual exhaust the rest is all stock.

 

Dude, you need to get a reputable tuner to write your tune, IE call Troyer TODAY before you end up damaging something you wish you hadn't.

I don't know your buddy, but just with my brief conversations (each lasting 30 min to over an hour) with MT, and with talking to my local guy who's a mustang tuning guru, writing tunes for these new trucks isn't something just anyone can do. If your guy is confused, that's not a good sign!!!

Take off the 3.5 AF1 return tuning to stock, call Troyer Perf to get the best tune available for the F-150!

Good luck!
- NCSU

PS: The MAF transfer function does have to be altered when using the 3.5" AF1, now what actually gets changed/altered, I have no idea, that's why I let MT do his thing.

 

Hi & Welcome;

You can use the Advanced Search feature here to pull up several previous posts that discuss this, but in brief, you buddy needs to rewrite a new MAF transfer function for that intake. This is not trivial as it will require precise datalogging to do it accurately.

The reason it runs part throttle and throws codes at WOT is, at part throttle ( closed loop) the PCM is using feedback form the O2's to control the A/F's. At WOT and/or at high loads, the system goes into Open Loop, where the A/F's are set by a pre-coded table in the PCM. That table is the transfer function that describes the behaviour of the intake at varous mass flow rates, that are within the MAF's range to measure. The 3.5" behaves significantly different than the stock unit, and if not properly dialed in can cause the truck to run lean.

If in doubt, your /your buddy may need to consult a more experienced tuner. Be aware though, that given the effort involved, the transfer functions may be considered intellectual property and hence proprietary.

You can ask SCT directly if they will supply a TF for an AF1 3.5" - dunno if they will or even have one, but it doesn't hurt to ask.

Meanwhile, put the stock intake back on and retune to stock or a safe custom tune, until this has been addressed.

This is a simplistic explanation - my apologies. As I said , please Search for additional insight.

Here's a few to get you started:

https://www.f150online.com/forums/sh...6&postcount=14

https://www.f150online.com/forums/sh...42&postcount=3

https://www.f150online.com/forums/sh...7&postcount=90

Good luck!

Cheers
Bubba

 

I got a 3.5 AirForce One installed on my 2005 150 supercrew, and got Mike to tune it and had no problems with a CEL. I recommend you call Mike and get hooked up. He is very intelligent, and will explain everything over the phone. Once he gets talking make sure u got some time to listen, hehe. Anyone who has talked to mike knows what I'm talking about. But anyway just give mike a call he will help u out.

 

Hi Brack,

I do NOT mean to sound rude, but your buddy must not know about tuning mass-air vehicles, as this is something so basic, obvious & easy that anyone who is actually any kind of tuner could have fixed this with proper datalogging and dial in the A/F's completely from scratch across the entire throttle position range from idle to WOT and any rpm or load in a couple of hours on a vehicle with no mechanical problems. And they would know what to do right away, with no questions whatsoever.

I do not like or mean to slam other tuners, please understand - it's not nice, I don't care to do that, or have it done to me. And so I hope you understand I am NOT trying to slam your buddy - but you have a *serious* problem there that requires immediate correction, and anyone who is actually a tuner would know right away what to do about it and be able to do it on their own - anyone who can't has no business whatsoever even LOOKING at the PCM, much less putting tunes into it. That's the deal.

The bottom line is what you need to do is call us and have us do *proper* tunes for that vehicle, as I can send you tunes that will put your A/F ratios right where they belong, and get rid of those codes - that is, assuming you do not have *mechanical* problems.

I will not tell you how this is done, but I will give you a hint - the only place where the PCM is going to warn you of a lean or rich condition is in closed loop, meaning lighter throttle and lighter load conditions, because that is the only time the PCM it looks at the O2 sensors for the purpose of A/F ratio feedback control - the PCM does not look at the O2's for A/F control at heavy throttle, and you are NOT safe driving around only at light throttle without proper tuning. In other words, you could not *possibly* be running lean only at heavy throttle but still be throwing codes - the system simply does not work like that.

Anyway, you need to call us and have us do your tuning to get it done right, my friend. I wish your buddy all the best, but I suggest you have us tune the vehicle.

Best of luck whatever you decide - and by the way - until you do have proper tuning TAKE THAT INTAKE KIT OFF and put the stock intake back on - otherwise you risk engine damage. You are NOT safe just driving it around on light throttle! Your tuner friend should also have told you that, too, by the way.

I wish you both well,