Exhaust Question

2007_Crown_Vic

Active Member
Aug 19, 2016
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Hi,

Don't worry, this isn't a "what exhaust sounds best" question, lol. It is just a technical question about future options. I am looking at changing the exhaust system that is on it now (I think it is stock with flowmaster.... 50 series or even 60 series mufflers) to the Flowmaster 17116 catback system that has 44's.

My question is if I do this and next year I decide I want to get that offroad H pipe everyone seems to like, is that as simple as just unbolting where the new flowmaster catback system connects and unbolting the cat section from the exhaust manifolds, then bolting the h pipe in its place, or is the h pipe designed to be used only with headers..... as I type that I realize that is likely a stupid question because if I am going to go that far I might as well get the headers to right, lol. Either way, the question still stands for information purposes.

I guess that adds a part three to this - if I just do the catback now, can I later unbolt the cat section and the manifolds and bolt the headers and h pipe in its place?

Thanks for any help. It is getting close to time to wake the Mustang up after it's winter sleep, I can't wait.
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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polk county florida
Simple answer is not that simple, for the most part if your mustang has factory headers most aftermarket H pipes will state if they bolt to factory exhaust headers, if you replace your exhaust with a 'cat back' system first then later you replace you cats with an 'off road' H pipe get it from the same manufacturer, you likely will have to visit a muffler shop to get it tweeked to fit good but not always. Headers are another subject.
Now my opinion, if you are planning on replacing your headers along with the rest of the exhaust system I'd start with the headers, then if you feel the need, replace the rest of your system using the same manufacturer, keeping in mind that if you remove the cats and install an 'off road' H pipe you will not pass an emissions inspection.
 

2007_Crown_Vic

Active Member
Aug 19, 2016
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Thanks, good points. I didn't think that keeping brand specific would be a good idea. I will do that. It is almost bone stock and used as a summer daily driver so I will price some stuff out and see how much of the exhaust I want to replace in the end. Luckily for me, where I live most people don't even know what an emissions inspection is. Basically as long as the car had a valid safety inspection when you bough it or you have one done once it is in your ownership it never has to be done again as long as you own the car so I am good there. All mine needed was the hatch lift supports and the daytime running light module.

I am thinking the best thing to do here is to just get (brand specific as you suggested) headers, h pipe and flowmaster system so it can all be installed and fitted at once. Hopefully the wallet allows that to happen.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
17,792
5,770
193
polk county florida
Some advice here, keep you factory cats after you replace them, they are getting hard to find and pricey if you need to put them back on, as far as that goes keep anything thats factory installed that you replace with aftermarket parts except after cat exhaust pipes, later on you'll be glad you did.
 

2007_Crown_Vic

Active Member
Aug 19, 2016
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Funny you mention that - I am keeping everything original to the car, even the old worn out hatch lift supports. It took a lot of looking to find an original almost stock foxbody that wasn't rusted out locally. I will definitely keep the cats on the off chance they ever need to go back on for some reason or if someone else is in need of them. If nothing else if I ever sell the car again it might be a nice touch to have a lot of original parts to go with it.