I have a 2014 Mustang gt i recently had a flowmaster Cat-Back Outlaw series exhaust installed on it but since this was done i cannot drive it due to exhaust leaks,exhaust rattles,extremely Loud, took it back they got the exhaust leaks fixed i think,the rattles more than doubled in annoyance and it is still extremely loud, the kit came with a x-pipe scavenger,mid pipes and mufflers my question is if i take the flowmaster system off and revert back to stock (found one that wasn't hacked up) my question is will the oem pipe fit back on or did they have to modify the factory front pipe i found the install instructions and it says that you need to drop the front pipe to reuse the clamps, my question is do i need a new front pipe as well
going to check tonight if the rain stops but would like to get cat-back system off before it gets many miles on it...OUTLAW SERIES NOT RECOMMENDED FOR CONVERTIBLES

 

First, please ensure I'm right in saying this is the system in question that was applied, and you don't care for:
https://www.holley.com/products/exha...s/parts/817590

If so, the instructions:
https://documents.holley.com/817590.pdf

does not say that the front pipes... aka the headers, exhaust manifolds, that sort of thing... and catalytic converters are included in all that... needs to be messed with at all. The old system from the secondary catalytic converter exit to the muffler tips is what's taken out and replaced. Therefore if you've found all the system from that point back, then they should just line up and go. The only thing I saw is the clamp that goes on the cats that's *attached to the xpipe* must be moved over to the new system. So ostensibly if your 'new' pipe doesn't have those on it, you'll have to move those clamps.

What you may have been reading is the 2015-up version, where you do have to cut the pipes. This is not that kit. It should just bolt back together, if what I'm reading is correct. I cannot find any video that shows the install on this particular car. Or even the '05-10, which is similar, I believe. Axle-backs? Out the wazoo. But cat-backs? Good luck finding that. Unfortunately. But maybe that's because it's not hard to do them, because no cutting?

I dare say that many exhaust systems out there aren't all that great for convertibles unless you just want loud/noise. But then I can say the same thing for 'because racecar' suspensions for any car. Noisy dang things when you do that. All the bumps, all the squeaks, all the rattles, but dang, does it handle, right? I wouldn't trade my suspension mods for quiet any day of the week, I'll tell ya. Noise means nimble.

Anyway. I hope that helps!

 

i just inherited the complete exhaust system from a 2014 mustang gt Mufflers,Intermediate Pipe,Resonators. I was just at the shop to have it put back on and low and behold the Front Pipe right after the cats that contains the factory H-Pipe so the factory exhaust can be bolted back up is missing.. i inquired about the front pipe i am missing but NO auto wreckers where i live seem to have one, so i called the dealership and the cost of the pipe is $400.00 and will be about 2 weeks out so i am going to have to drive the car for 2 weeks while i wait for the parts to come in, if the installer didn't need to cut the factory H-Pipe why didn't they ask if i wanted it back when the exhaust was changed..

 

if i was thinking when i got it i should have just gone for the axle-backs and left the factory system alone i can always change mufflers by loosening the clamp and swapping it out

 

well i should have listened to that little voice in my head saying keep the exhaust as i just had the CEL come on:

P219A Bank1 Air-Fuel Ratio Imbalance
Severity Level:Severe 3 of 3

Scanner Report: Results
Fuel Sys 1 CL
Fuel Sys 2 N/A
Calc Load 74.9 %
ECT 192.0 F
STFT B1 -0.78%
LTFT B1 5.47%
STFT B2 -3.91
LTFT B2 1.56%
Eng RPM 1950
Veh Speed 31.07 MPH
Spark Adv 29 Deg
IAT 66.20 Deg F
MAF 6.62 lb/min
TPS 26.27%
O2S B1S2 0.13V
STFT B1S2 99.22%
O2S B2S2 0.84V
STFT B2S2 99.22%
Run Time 429 Sec
Command EVAP 100%
Fuel Level 59.22%
Warm-Up DTC Clr 6.00
Clr Dist 85.75 Miles
EVAP_VP -4.28 InH2O
BARO 28.06 inHg
LAMBDA B1S1 1.00
O2S B1S1 -0.20 mA
LAMBDA B2S1 0.98
O2S B2S1 -0.10mA
CAT Te 11 1118.84 Deg F
CAT Te 21 1118.84 Deg F
ECU Volts 13.61 V
Load Value 51.76 %
EQ Ratio 0.98
Rel TPS 14.12 %
Ambient 60.80 Deg F
TPS B 40 %
ACC Pedal D 29.02 %
ACC Pedal E 14.12 %
Command TAC 21.96 %
CEL Status ON

this all started after i swapped to the flowmaster Outlaw Cat-Back Series exhaust i am swapping back but when i pull up the results tab on my scanner it says:

TSB 14-0120
Issue: Some 2012-14 Mustang Vehicles equipped with a 5.0 L engine and automatic transmission may exhibit a malfunction indicator lamp illuminated with DTC P219A or DTC P219B stored in the PCM

so is this a air/fuel issue or a transmission issue the TSB says that Ford needs to reprogram the PCM.. is this a computer fault or a fuel fault or exhaust fault i will be putting the stock exhaust back on by next weekend never had an issue before the exhaust was changed

 

That's probably coincidental to the exhaust issues you're talking about.

Here's the list of things that code would get thrown for:

• Leaking or contaminated fuel injectors
• Low fuel pressure or running out of fuel
• Leaking evaporative emission (EVAP) canister purge valve
• Exhaust or intake air system leaks
• Exhaust gas recirculation (EGR) system
• Positive crankcase ventilation (PCV) system is leaking or the valve is stuck open
• Ignition system
• Incorrectly seated engine oil dipstick, tube or oil fill cap

That said... https://themustangsource.com/forums/...tsb14-0120.pdf

That shows that if that code is the only one in there, then there PCM needs reprogramming to the latest specs. The O2 sensor and the fuel trim data you provide doesn't indicate anything odd, or something would stick out badly on Bank 2. It doesn't. It doesn't even show the sensors aren't working. It does show a little bit rich on bank 1, but no big, that's almost normal.

So yeah... it may be that your PCM is needing a reflash due to that particular oddity TSB. Maybe. It's not a transmission issue, it's a computer issue because the programming for the automatic has a slight error in it, hence the need to reflash in this case. Or so it says.

It's possible that all the messing around with the exhaust has caused one of the above list items to happen, but you'd think there'd be another code thrown with it. Say the O2 sensors got damaged, that's a whole other code... Can't think of anything else other than air getting in where it's not supposed to that'd cause a problem...

 

i have it booked in tomorrow at 9:45am to have it re-flashed the service tech said he has never heard of that particular code so i told him that apparently after i scanned it and hooked it up to my computer the tsb came up on the screen i gave him all the information i had and he said the exhaust should not make a difference but you never know, then i hear that the flowmaster outlaw system is a bigger pipe and cools the exhaust too quickly and without programming the car for that mod it will throw a code.. so i have to order a factory H-Pipe while i am there so i have everything to do the exhaust swap then i can sell the cat-back exhaust to someone else

 

Sorry to hear you're having so much trouble.
Not sure if these will help but here's the exhaust diagram for the 2014 Mustang.
Exhaust Components for 2014 Ford Mustang

Also check the pricing, $400 seems too steep for factory H-Pipe alone. Have the dealership match AutoNation Ford. I would wait out until factory exhausts are put back before flashing the PCM.

 

hmmmm . . . I haven't followed every detail of this thread but just going back to basics: "cat back" means the changes were from the catalytic converters back, right? So that means the front O2 sensors were not affected at all, and most likely the rear O2 sensors also were not touched, right? If that is correct then the exhaust changes should not make any difference to the O2 sensor readings and should not be causing the codes. I think that what you heard about "cooling the exhaust too quickly" applies to long tube headers and high flow cats, or anything that is up-stream of the O2 sensors; I'm pretty sure that downstream changes should not make any difference.

 

Why don't you hit up a junkyard... er, salvage yard... and get the X pipe there? Be cheaper... I know it's a hassle but they got to have one lyin' around somewhere, yeah? Be what I'd be doin', for what it's worth...

Just a thought. You do you, and I hope it gets solved soon!

 

ok just a little update, i did have to pay 363.18 for the factory H-Pipe and and another 100 for 2 clamps, see living in canada has advantages and dis-advantages.... mostly dis-advantages when it comes to car parts as soon as they cross the border there is like a 400% mark-up on them, i did try calling every salvage yard locally to me but it seems that we don't have ANY 13-14 gt's in the salvage yards and by that i mean none..... i did have 1 person offer me a used one for 350.00 but for the extra 10 bucks i went new...

had the car re-programmed and light has been off since just seems there is more lag by the drive-by wire acceleration, will definitely be looking for a sct x4 programmer just so i can adjust the throttle delay

well summer is here maybe i'll finally get it out and drive it more but the way insurance is here it plain nuts because it's a sportscar i pay 2800 per year for insurance and 1388 for 6 months so if you think your being screwed over by your insurance company come to Vancouver,BC canada and insure your car....we have 1 insurance company and you pay what they tell you to pay...hell i was told i had to put storage insurance on the car when i cancelled the insurance, i opted out and said you can't make me buy insurance for an un-insured car