I just recently bought a 2013 GT and am having some issues. The most notable one and the one that seems like it probably umbrellas the other minor ones is my wide open throttle pulls. The motor is stock and safe even from bolt-ons or a tune. When I'm in 3rd or 4th gear, the power can suddenly drop and feel like I've got 250hp for a second or two and then get back into power.

Now I've taken it to a ford dealership three times, one for misfiring codes, where they 'relearned the misfire' and made the car stop spewing codes. The second time, they replaced the crank position sensor o-ring. The third, they replaced a pcb valve hose due to low barometric pressure, which did increase with the new hose. The car has a sputtery idle that noticably and randomly shakes the car for split second. It's sucking up too much gas and backfires like crazy, but to be fair, it doesn't have mufflers.

Before any of this went down I replaced both the spark plugs and ignition coils. The plugs are OEM and the coils are SR performance. Ever since the 'relearn' no P030X codes have been sent. I have a couple varying codes for the abs system due to the lack of a sensor because the previous owner stuck some disgusting 22 inch pimp rims on it. I've told the dealership about the loss of power all three times and nothing has changed, if anything it's gotten worse. The very first time I took the car to someone it was an independent mechanic who told me to relearn it as well, and i also want the reassurance of repair insurance a dealership offers so i would need a good reason to take it elsewhere (other than the obvious fact they haven't procured a solution to their own damn car's problem).

ALSO: Don't mention a dealer warranty It's out of every possible warranty and I'm on my own to figure it out.

 

My AFR drops from the 14 it's usually at during wide open pulls to about 11.6 right when the power drops out and then back up as soon as I get it back. I then looked that concept up and according to most people it's supposed to ALWAYS be that low during a wot pull so wtf. I seriously need help because I'm pretty sure this dealer is milking me for an issue they probably already know of.

 

You could try cleaning the MAF sensor.
I'd also suggest that you buy an ELM 327 Bluetooth module that plugs into your OBD 2 diagnostic port, and download an engine scanning software such as Car Scanner onto your smartphone. The software will connect via Bluetooth to your ELM 327 and has the capability to monitor live data from your ECU. This will help you troubleshoot the problem by effectively making you your own car doctor.

 

have you tried reinstalling the original coils to see if the problem goes away? The Oems are the best quality part and most often, aftermarket “performance” ones and generic replacements (no matter the brand) cause problems.

 

After checking the MAF sensor and cleaning it, the problem persists. It could be a million things according to further research I've done, and I think the best thing to do is take it to a coyote tuning shop near me that I found.

 

Unfortunately I'm a dumbass and didn't keep the originals. My next step with them is to buy a tester for cheap and see if I can find a problem.

 

Be careful with going cheap, a lot of those are bad out of the box. When you get that misfire code again swap the misfiring coil with one from another cylinder and see if the misfire follows the coil or if it stays with the same cylinder. Same cylinder could be a spark plug, ignition circuit or fuel injector.

 

well the car isn't dishing out misfire codes anymore. The power dropping out frequently is my issue but I see what you're saying. This is the plan.

 

Then drive with a buddy and have a live-data type scanner. Drive it to see which cylinder is misfiring while driving and then try the swap.

 

Out of curiosity, do you have a tune on that? if so, who did it.