2 catalytic converters?

[phillymscott]

So i was puttin a new muffler on my 97 explorer sport and i saw that i have 2 cats. Anybody know if this was standard for my explorer and if i can legally take at least one off to try and get a louder sound. i live in NC and im pretty sure the law is you just have to have one cat, never really knew they could come with 2.

 

[techieman33]

You probably have 3 and maybe 4 cats actually. It changed a couple of times over the years. And no you can not remove them legally. It is against federal law to remove any emissions device from your car.

 

[ranger7ltr]

Feel lucky;My 99 Sport has 4 cats...

So i was puttin a new muffler on my 97 explorer sport and i saw that i have 2 cats. Anybody know if this was standard for my explorer and if i can legally take at least one off to try and get a louder sound. i live in NC and im pretty sure the law is you just have to have one cat, never really knew they could come with 2.

And yes it is standard...

 

[Electrohacker]

if your state has inspections or emissions then you cant remove them. if it doesnt then you risk a cop being an ass and looking under your truck to give you a ticket. honestly if your truck isnt loud they wont look.

but you need the primary cat's to maintain proper engine performance due to sensor location and engine back pressure

as far as I know though only the V8's have secondary cat's (yes the V8's have 4 cats!!!)

 

[phillymscott]

o well alrighty, pretty lame though

 

[2000StreetRod]

Less restrictive

My 2000 Sport has a cat for each bank that results in less restriction than if there was only one cat for both banks.

 

[ranger7ltr]

V6's also came with 4 cats...

as far as I know though only the V8's have secondary cat's (yes the V8's have 4 cats!!!)

The picture shows the primary cats in the down pipes coming from the manifolds then that bolts to the pair of secondary cats that are inline that then attach to the muffler...

The second pic shows the replacement parts for the front and the rear cats on a 4 liter ohv...

And, no, this is not the bottom of my truck...Just one that shows the underside exhaust and other components...

 

[Electrohacker]

well sir, you win the trophy for finding the craziest setup i have ever seen.

you should be able to eliminate the secondary and tertiary cats and still be legal in states without inspections since most cops only look to see you have A catalytic converter

 

[ranger7ltr]

Actually I plan a different exhaust setup...

I plan on replacing the primary convertors with a set of Thunderbolts welded into the same pipes then the flange removed and the two pipes run into an X pipe fitting...Or ideally I would like to increase the primary pipe size to 2.25" since that is the piping size I am using throughout the rest of the system...

Then the two pipes from the X running into individual Thunderbolt convertors then each pipe running into a dual in/dual out Magnaflow muffler...

My dillema is how to terminate the exhaust from the dual out muffler...I will need to get the truck to the exhaust shop for them to measure to see if i can run a pair of 2.25" pipes in the same area under the truck...

I will keep the convertor arrangement from the engine down to the connector pipe but open up the exhaust at that point... The y-pipe is not a Y after all but a pair of pipes dumping into the front mouth of the first of the inline pair of convertors...

And with my new engine, I believe the 2 downpipe convertors are partially restricted and with 170k on them they have served their purpose...

 

[silentchris]

anywhere you dont have emissions you can take all the equipment off the federal requires new vehicles to be sold with the equipment the first thing in northern virginia everyone does when a car hits 25 yrs old is yank all that stuff off most places require emissions on all obd2 vehicles so you probably wanna keep those cats on or replace them with high flows

 

[ranger7ltr]

Removing the emission equipment is not an option...

Since it is a Federal offense to remove emission equipment from a vehicle that came with it...And in Texas we check for the equipment being in place even if the county doesn't check the OBD II status...I even have convertors on my V8 Ranger...Plus I am using an Explorer OBDII harness and PCM in there to control the engine...

My old Ranger came with emission equipment that I have updated to match the output of the then current engine I installed...One, to match the requirement of the equipment being there and, two, to facilitate the yearly inspection that I would have to have done to drive it on the street...And it is 26 years old so it is exempt from a safety inspection but not a visual emissions inspection...

 

[Brandon96]

The picture shows the primary cats in the down pipes coming from the manifolds then that bolts to the pair of secondary cats that are inline that then attach to the muffler...

The second pic shows the replacement parts for the front and the rear cats on a 4 liter ohv...

And, no, this is not the bottom of my truck...Just one that shows the underside exhaust and other components...

My '96 OHV has the EXACT same header to muffler set up as the one you have pictured, however I do not have the two converters that are on the y-pipe (the second picture). Instead, I just have... pipe... I do have those two big son-of-a-guns on the downpipe? I guess you could call it.

It's all factory... I find that sorta interesting....

 

[silentchris]

holy cow i just read texas emmision laws wow oh and once a vehicle hits 25 here its an antique and we can pull all the parts off we want

 

[ozmedia]

You need to read them again, you can't really drive it on antique plates

holy cow i just read texas emmision laws wow oh and once a vehicle hits 25 here its an antique and we can pull all the parts off we want

It's not so cut and dry. While in many states the vehicle has to be in original condition with no upgrades, Texas State DOT only requires that the vehicle, frame and motor are 25 years old....BUT...with antique plates you can't use it as a daily driver.

From Texas DOT

"The frame, body and motor are at least 25 years old, and the vehicle is a collectors item that is TO BE USED SOLELY FOR EXHIBITION,CLUB ACTIVITIES, PARADES AND OTHER FUNCTIONS OF PUBLIC INTEREST (replicas do not qualify for antique plates). THE VEHICLE WILL NOT BE USED FOR REGULAR TRANSPORTATION except when routine maintenance is needed. the vehicle will not carry advertising."

SOURCE: TEXAS STATE DMV ANTIQUE VEHICLE REGISTRATION FORM: http://www.txdot.gov/txdoteforms/Ge...eportError.jsp&configFile=WFServletConfig.xml
BS'ing them and getting caught on it is a third-degree felony.

Not such a great idea, just to make a vehicle SOUND cool.

So, as you can see, just being old doesn't really help you work around emissions tests, in fact these rules were specifically written to stop people circumventing emissions testing once the vehicle is of a certain age.