Putting cats back on the mustang...

[Sytx]

I just recently purchased a 2017 Mustang GT, all stock except for the exhaust which is entirely straight piped - from tips to manifold. In my area it would be safest to put cats back on the car, I'm trying to find high-flows that will pass emissions and eliminate the CEL.

I found some universal Magnaflow high-flows, part #53956. (MagnaFlow 53956 - MagnaFlow Universal Spun Catalytic Converters)

Will having two of these welded back in work just fine?

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[FreePenguin]

what about the tune? if your car is straight piped, that means its most likely retuned, or running poorly.

exhaust after the cat doesn't matter, just sounds. but the cat being removed, or changed to a different cell count alters the tune, or atleast it should.

so if you are tuned, you will need a retune with new cats. and there's no guarantee you'd even pass emissions with aftermarket cats. thats my opinion. only guarantee is, OEM cats, with oem tune, or ford perf tune. as those are designed / made for each other.

would it be easier to find take off headers that someone took off to put aftermarket headers on? OEM cats >>>> better quality than majority of aftermarket cats.

 

[Sytx]

Are you sure there's no cats? it would be apart of the header I believe (I am ecoboost) but I seen enough of the GT post, that the cat, should be on the headers., he could of straight piped the exhaust after the headers. it would be loud as hell im sure.

Yes there are no cats, I had the car lifted and checked. As far as the tune goes, I'm not sure it has one. Nothing about a tune was mentioned during purchase. The car does still have factory warranty left on it, I'm just trying to avoid voiding anything and making sure that there aren't any issues.

 

[Sytx]

what about the tune? if your car is straight piped, that means its most likely retuned, or running poorly.

exhaust after the cat doesn't matter, just sounds. but the cat being removed, or changed to a different cell count alters the tune, or atleast it should.

so if you are tuned, you will need a retune with new cats. and there's no guarantee you'd even pass emissions with aftermarket cats. thats my opinion. only guarantee is, OEM cats, with oem tune, or ford perf tune. as those are designed / made for each other.

would it be easier to find take off headers that someone took off to put aftermarket headers on? OEM cats >>>> better quality than majority of aftermarket cats.

I can find the OEM ones, but I'm just trying to avoid spending $1k+ on oem cats if possible.

 

[FreePenguin]

Yes there are no cats, I had the car lifted and checked. As far as the tune goes, I'm not sure it has one. Nothing about a tune was mentioned during purchase. The car does still have factory warranty left on it, I'm just trying to avoid voiding anything and making sure that there aren't any issues.

its very possible, I am not sure a lot of mustang owners would delete a cat, entire exhaust, and not retune it. I could be wrong.!

myself, id be looking for a take off GT full exhaust. ive seen them sold on here, like hundred or two hundred bucks. people get new exhaust and completely remove old ones. look around. Would be the easiest swap, other than I hear, that headers absolutely fucking suck to swap.

dont buy a cat new, ive seen FULL headesr+exhaust for just a few hundred bucks on the ad section over time. check here, and mustang s550 parts group on Facebook.

make a wanted post. maybe someone has it put up in garage near you, but hasn't listed it, see your wanted ad, and contacts you. cant hurt to try

 

[FreePenguin]

I think you can find out if its tuned, if you hook up forscan to the car, (I could also be wrong) but when I hook up forscan, its a program you download on laptop and buy a cheap dongle for. when I click PCM, it shows me the tune files loaded on my car. ie. mine has the title for the ford perf tune for my mustang. stock would be something else. Aftermarket, I am not sure what those tunes would be labeled, but it would be different than oem name.

 

[Sytx]

I think you can find out if its tuned, if you hook up forscan to the car, (I could also be wrong) but when I hook up forscan, its a program you download on laptop and buy a cheap dongle for. when I click PCM, it shows me the tune files loaded on my car. ie. mine has the title for the ford perf tune for my mustang. stock would be something else. Aftermarket, I am not sure what those tunes would be labeled, but it would be different than oem name.

Thanks man, will try the classifieds first. I plan on getting my own tune for the car, wanted to get the exhaust under control first. (I never realized how loud catless straight pipe is, god)

 

[K4fxd]

Did you buy this from a private individual or a dealer

 

[Sytx]

Did you buy this from a private individual or a dealer

Dealer

 

[FreePenguin]

Thanks man, will try the classifieds first. I plan on getting my own tune for the car, wanted to get the exhaust under control first. (I never realized how loud catless straight pipe is, god)

and smells.

not all dealerships check for a tune/flash back to stock. but if it was flashed back to stock ,and you are hatless, you are not running optimally. that much I can assume and probably be accurate.

ive actually read a few people on here buy cars from dealerships as CPO, and found out it was tuned, etc. cant recall what they had done. but an engine blew on one of them and found out it had a tune when eh bought it. I am pretty sure the dealership covered the car though as it was their fault. This particular car I believe was an ecoboost I if I recall. LSPI ecoboom, something more prominent on ecoboost, I dont know if it even happens on GT's actually.

 

[Sytx]

and smells.

not all dealerships check for a tune/flash back to stock. but if it was flashed back to stock ,and you are hatless, you are not running optimally. that much I can assume and probably be accurate.

You are probably correct. It does feel a little bit sluggish

 

[K4fxd]

Under federal law they have to make the car compliant with all emission controls.

Show them it has no cats and make them fix it.

This is a reason for a mechanic inspection B4 you buy.

 

[FreePenguin]

Under federal law they have to make the car compliant with all emission controls.

Show them it has no cats and make them fix it.

This is a reason for a mechanic inspection B4 you buy.

Id do this asap. like, tomorrow. he has a point, I do remember dealership cars having to have emission compliance to be federally compliant at the time of sale. if you wait, maybe they will claim you did that to the car.

 

[Sytx]

Under federal law they have to make the car compliant with all emission controls.

Show them it has no cats and make them fix it.

This is a reason for a mechanic inspection B4 you buy.

I had one done prior to purchase. I told them that is what it was, they offered me a chunk of my down payment back to be able to take care of it and pay for it, while keeping the cost of the car still lower. They didn't seem to take too much care in the emission compliance on their part.

 

[K4fxd]

So they offered to make it right and you refused, now you want it correct.

I believe in the classifieds there is a set of stock manifolds and cats for sale.

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