My response to this: Return to stock air box and tune. Next, call CAI manufacturer and ensure you have what you think you have. Size of air induction tube, i.e. 88 mm, 110 mm, and if it has an insert in the tube or not. The insert would allow the MAF to read properly for automatic transmission and allow it to be use with stock tune. This tube diameter matters! Afterwards, I would plug in the hand held tuner and read the ECM code...not what it says on the outside on the box under the hood, but what code the hand held tuner gives you. At this point, I personally would call Brent White from Brenspeed, but there are other quality tuners, and give them all the information they ask for. Tell them what has happened in the past...make sure they know...they will ask you to look for any unknown modifications or plug the hand held tuner in and data record for them. Your tuner should have done this work already. If it was in fact the tuner I mentioned, they will make it right, trust me. I suspect it was someone else, because he has done all my tunes and he goes out of his way to make it right. Additionally, this new tune costs about $95. The wrong tune could cost you over $6,000 to replace or repair a damaged engine. You tell us about saving for tires and wheels...those things are so superficial...vanity...do you want a good look Mustang that doesn't run? $95 is chump change...an oil change cost. Get that engine right is your priority. Those tires and wheels are only going to be delayed about a month.

 

If I flash my car back to stock, does that essentially "unmarry" the tuner? It's a SCT X4. I'm 99% sure the MAF sensor is connected correctly and facing the right direction. I also checked all connections and potential air leak locations and its solidly connected everywhere.

 

Yes, it should. When I return my vehicle to stock to update the handlheld firmware it shows "unmarried"- as if it were never on there.


Watching again I'm 99.9% certain the wrong value file is being loaded for the CAI/ MAF table re-scale. It's a super simple mistake and very easily correctable. Seems as if your tuner is making an error here (either loading the wrong file- perhaps the one for the intake tube WITH the insert, when you don't have it... if I'm following correctly...) would be all it would take. Or perhaps less likely loading/importing value files in an incorrect order. Where are you located? If you were in CO I'd fix this for you just for ****s n' giggles.... Surely someone near or close to you would be willing to do the same? While that sound is scary, nothing bad is actually happening... I wouldn't drive it like that but I assure you in troubleshooting, nothing is going to become damaged....

 

I'll say this again. I don't think it's a tune issue. One thing the OP said. The noise goes away after a couple of minutes. If the tune file had an issue the condition would be present at all times. I am sticking to some type of vacuum leak post MAF and when the PCM goes closed loop it's compensating. The noise is definitely backfiring through the intake which screams lean to me. It's also impossible to bolt the MAF in backwards as the bolt pattern won't allow for this.

I would re-install the factory airbox, reflash to stock (no this won't unmark your SCT provided it's the same tuner you used to upload the existing file).

Of course if the OP had access to a smoke machine we could verify any type of vacuum leak between the MAF and TB. A cheap way of doing this would be to grab a propane torch and simply turn the gas on and hold the torch tip close to all fittings and up and down the plastic tube. If the engine RPM surge upward while doing this you definitely have a vacuum leak.

Not saying it isn't the tune file but because it runs out after a couple of minutes my gut is telling me it's a lean condition being compensated for once it goes closed loop.

And of course. Unless you're making more modifications to you car I would keep the factory airbox and just get an aftermarket tune for the stock airbox. The HP gain is in the tune and not the CAI. The CAI may make a mean sound on WOT but there is no HP difference from a stock airbox with a tune vs. a CAI with a tune on a stock car.

 

Just wanted to say thanks to everyone for the input. I appreciate it very much. I did put the stock kit back on and flashed it back to stock with no issues. I'm also going to run by a local speed shop and just talk to them a bit. I'll post an update once I know more.

Thanks again-

 

Thats what I mean, the air from the CAI needs to pass through the opening in the meter. You can install it wrong by having the opening facing the wrong direction.
You have 2 screws one in upper left and lower right, rotate it the wrong way and they still match up to the intake.

 

Mine do no match up at all if reversed...top pic is correct way. Second one is reversed and holes do not match up at all:

 

Another sort of obvious indicator is that there should be a slot on one of the thin sides. That should be on the in-flow side. It won't have it on the other.

Forgive my crude cave art:
(cone filter) -> slotted side of MAF -> more tube -> (intake/tb)

 

Took it to local speed shop and got it checked out with stock kit and it flashed back to stock. Spun it on dyno and it ran good. Will likely just leave as is for now.