That's what my local Tuffy dealer said. Reconfiguring the original manufacturers design is against EPA regulations and punishable by fines. So, he says he WILL not cut out the Y-pipe and run true duels on late model trucks. It's OK on models before 1980. He can cut the pipe after the Y (and the O2 sensor) and replace the pipe on back with SI-DO and a performance muffler. So a "catback" system then is not really from the cats back? It's from the Y back or a "Y back system", huh? What do you think? Is he blowing smoke up my @ss? I'm tending to believe him, because why wouldn't he want to add true duels; it would be more money in his pocket.

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The GO 4D IT SuperCrew '01 SuperCrew XLT 4x2 (Generation II): 5.4L, Limited Slip, Black, 5-Spoke Rims, Dark Cloth, Capt. Chairs, Power Seat, Steps, Extender, Moonroof, 6-disc manual CD changer; Ford/Duraliner, '86 Mustang rear mats as humpmats, K&N Filter, Ford molded rear mudflaps.

(for sale) The GO 4D IT Ranger: '93 Ranger XLT SuperCab 4x2: 65K miles; 4.0L; Limited Slip; Black; Alum. Rims; A.C.; Power windows, mirrors, and locks; CD Player; Hard Tonneau; Running Boards.

If it weren't for trucks, we wouldn't have tailgates.

 

As far as I know, true duals are perfectly legal as long as the cats are not removed. It is also law( I think) that they can't be replaced before 50,000 miles.

 

exhaust guy told me the same thing. He put true duals on a mustang I had which originally had the same configuration as the f150, but he said there's alot of difference between an f150 and a mustang.

 

Check into it GO 4D IT, it might be a law in your state. Not here though, i've got true duals on my 2001 Screw.

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2001 SuperCrew ORP 5.4L
MODS-Ramsey Brush Guard and Pro Plus 9000 winch, MAAP steps, Airaid, True Duals w/ 50 series muffs, Line-x, and huskyliners.
http://albums.photopoint.com/j/AlbumIndex?u=1508480&a=11420452&f=0

 

there is a law in some states that prevents muffler shops from installing true dual exhaust on trucks (i have no idea what the reasoning is behind it is though). call around, maybe you can find a shop that will do it for ya. good luck!

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1989 F-150 XLT Lariat: 2WD 5spd 5.0[*]3" Body Lift[*]33x12.50.15 BFG on 15x10 AR Rims[*]Rancho Steering Stabilizer[*]Flowmaster cat-back dual exhaust

 

I've got true duals,and I passed the visual and emission test.... This shop made me pull the tint off the top of the windshield,so they weren't lax on the inspection laws in my book. Maybe it's just in certain states,,,,98
You could always drive to Alabama to get it done(no inspections )

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98 F-150 4.6 Litre XLT2wd Ext. cab
Yokahama AVS/ST's
prarie tan/tan int.
K/N gen.II fipk
custom dual exh/gibson rectangle tips/rear exiting.
color matched snuglid
Superchip!!!
Clear front corners
Stillen Quad light air dam,Sweet!!
Euro taillights
Cobra 75WXST cb w/weather alert
[b]Kenwood cd w/Radio Shack speakers,don't laugh it sounds pretty good
Viper alarm
On the way/wheels,tires, etc..etc.......
the monochromatic boogie is done,cool!.
Come see my new pictures@ www.my-f150.com

officialtomwaits.com
reverendhortonheat.com

WOW,what a cool site!

FENDER GUITARS ROCK!!!

 

Hey man.. i live in alabama...don't be jokin on us..haha j/k

 

I am not sure on other states but in Texas there are three things they look at for exhaust inspection.

First, is that you have all four O2 sensors in the factory locations.

Second, that you have all your cats in the factory locations.

And Third, the exhaust must exit no closer than 15" from the cab of the truck(unless you have a camper which then it must exit the rear of the truck).

 

F150Freak,

I think you are right on what generally gets looked at. I did some digging on Texas law and found out that technically cutting the Y-pipe is not illegal. What it states is that the catalytic converters cannot be modified AT ALL. That means you cannot relocate them an inch even if the O2's stay in the same place relative to the cat. Since the pipe coming out of the cat is part of it (where the O2 is), you have to be careful where you cut so that you aren't modifying it, i.e. well beyond the O2. Since the Y has such a radical bend in it, some inspectors may just assume that you cannot modify the pipe without touching the part of the pipe you aren't allowed to and thus they mark it as illegal. It's sticky.

I was looking uder the truck and can't for the life of me understand why they put the Y where they did as opposed to back a little. Seems like the Y could have been more of a Y and thus fewer 90 degree bends. Oh well, they didn't ask me

Chuck

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2001 Gen I Screw Lariat
Air Raid, Superchip

 

Chuck, you are right that the cats can't even be touched, but on the later model F150s it is possiable to do true dual exhaust with out messing with the cats. The "Y" pipe on the later model is after the four cats our trucks have. I use to do Inspections in the DFW area so i made sure when I had my exhaust done it was perfectly legal.

On the pre 97 models though the "Y" pipe is before the cats which means the exhaust MUST be a single in dual out. In my opinion the way the exhaust is set up on the pre 97s is beyond my understanding, but I am not the genius that designed it.

BTW, I have true duals on mine(crossover AKA "H" pipe has been installed since pic)!

 

F150 Freak,

DFW isn't too much of a drive for me, I;ll have to look you up when ready for the exhaust mods! Did you do any dyno runs before & after the mod?

Chuck

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2001 Gen I Screw Lariat
Air Raid, Superchip

 

sorry, I have yet to get any dyno numbers on my truck. I wish I did have the before and after.

 

Thanks, Max Mitchell for answering this question with his reply from this thread. https://www.f150online.com/f150board...ML/000659.html
He found the EPA federal law, that includes you Texans, that true duals are illegal. http://es.epa.gov/oeca/ore/aed/comp/jcomp/j11.html Look at Question 7.
To me, it sounds like they don't want you eliminating the O2 sensor, which is sniffing the exhaust after the cats, to be eliminated. I don't know why you can't then cut the Y out, install an H pipe, replace the O2 sensor, and run true duals on back, allowing the O2 sensor to perform as normal. Maybe it's the back pressure issue, like the answer in Question 7 says.

But the law is still the law until it's changed. It looks like I'll get the single in-dual out setup.

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The GO 4D IT SuperCrew '01 SuperCrew XLT 4x2 (Generation II): 5.4L, Limited Slip, Black, 5-Spoke Rims, Dark Cloth, Capt. Chairs, Power Seat, Steps, Extender, Moonroof; Ford/Duraliner, K&N filter, Ford mudflaps, Tinted windows, Jason Dimension hard tonneau.

(for sale) The GO 4D IT Ranger: '93 Ranger XLT SuperCab 4x2: 65K miles; 4.0L; Limited Slip; Black; Alum. Rims; A.C.; Power windows, mirrors, and locks; CD Player; Hard Tonneau; Running Boards.


If it weren't for trucks, we wouldn't have tailgates.

[This message has been edited by GO 4D IT (edited 03-23-2001).]

 

You're more than Welcome. You cannot modify the section of pipe which contains the cats. Our cats are not bolt on; they are part of the pipe. This section is from the exhaust manifold to the first connection behind the Y-pipe. All cat-back kits connect behind the Y at the first connection because that is all they can manufacture legally. This article also answers all the incorrect posts about duals, off road pipes, and cat elimination. It is a federal law that supersedes all state laws.

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2000 F-150 XL, RC, LB, 5.4L, 4R70W, 3.55LS,
Class III tow, Payload #3, & Convenience pkgs.,
4-wheel disc/ABS, Chestnut/Parchment 40/60,
Ford bedliner w/Paintsaver & gas/wheel/spare locks,
K&N F.I.P.K. w/Outwears pre-filter, Superchip,
Dynomax ultra-flow welded 3" cat-back w/ 3" Y-pipe,
Hellwig front & rear anti-sway bars, Rancho RS 9000s,
Mobil 1, K&N oil filter.