So What Will Happen If I Take Off All FOUR Cats?

[DixieOnMyMind59]

Yes, I have no pre cats at all (actually no cats), and no CEL or running issues. The O2 sensor was simply put back into the pipe that took the cats place with a weld in bung. I'm not encouraging you to cut your's off just telling you my experiences. You could end up throwing a CEL or driveability issues. I just did not.

So i could do what you did and if i have an issue with the O2 sensor's readings i could buy some MIL eliminators to trick the computer into thinking i have cats.

Did you get an exhaust shop to weld in the bung? The shops around here won't help me with anything that has to do with eliminating the use of the cats.

Thanks,
Colton

 

[Turdle]

The shops around here won't help me with anything that has to do with eliminating the use of the cats

Neither should we--it is illegal

 

[Mutineer]

I have the rear cats removed, with "untuned" true duals in FM 40 series Muffs.

I have been running this for about a year now.

It sounds EXACTLY like that last vid of the 5.0L Mounty....

Issues include the Perpetual CE light mentioned before and the Exhaust is a little hard to take, also mentioned before.

Thats about it though.

I get about 15-18 MPG running 33's on the stock drivetrain (AWD AUTO)

Personally, I got rid of mine for weight's sake.

I am installing Torque Monster Headders as soon as they get here.

Just an FYI. As long as the thing as a set of cats (1 cat for each pipe coming off the motor that runs the length of the truck) it will pass visual inspection. (in Texas, in 2002)

What happens with your emmissions readings is anybody's guess.

Good luck, I hope you find what youre looking for!

Daniel

 

[Mutineer]

Neither should we--it is illegal

BINGO

10,000 dollar fine, as welll as a possible 5 years in jail. for each offense (again, Texas, 2002)

You have to do it yourself. I dont know of anyone who works at an exhaust shop that would fork over 10,000 dollars and 5 years so your truck can sound like a mustang.

again, Good luck!

Daniel

 

[Dan Whitaker]

Neither should we--it is illegal

What Jon said.

Cats are Federally mandated. That is why shops will not remove them. If the shop gets caught removing them it's big $$$$$$$

I had a 75 NOVA I played with several years ago & I was just wantig exhuast pipe to reun from the headers to the muffler which I was doing myself.
The exhaust shop would not even sell me the pipe because I was not running cats.

 

[96ExplorerSport]

Removing cats or gutting them can be be a bit tricky. It all depends which year your car is. If it's pre-OBDII, you can gut/remove cat and no CEL will come on. It's because pre-OBDII does not check for proper cat operation. OBDII on the other end has a secondary O2 sensor just to check cat operation. If you gut your cat, this sensor will throw CEL. There are ways around it, but I am not going to discuss them here.

How much will you gain/loose by running w/o cat depends on the car. Sports car crowd does this pretty often, especially with turbo engines. You get better spool and high-end power, but loose in the low-end a bit due to back pressure loss. This can be a problem for X, since you do not car about high-end, but you do care about low-end power. Thus, I would not suggest it for X.

 

[CDW6212R]

Ditto Jon, the subject went from obtaining a desired sound, to elliminating the cats, because other guys do it. Many of us tried to help, I suggested the best way to achieve the "sound." We weren't providing the answer required.

Al, all parts in a vehicle degrade over time, that's not an argueable fact. O2 sensors are known to degrade at some point past 100K or so. Let's not argue about when the blind squirrel will find a nut. Let's just agree that improvements can be gained by replacing most important parts. Regards,

 

[hunterdan]

If you remove all 4 cats you may not pass any state inspection. Even though you may not have emissions testing, they still might check for their presence. I would leave the front 2, or swap them out for the hi-flows mentioned earlier. If nothing else, have a set of downpipes fabricated to a larger diameter pipe, install a cat on each that will mount up like factory so that when you get the money for the TMHs, they will work and you wont have to change your exhaust around a second time. You will get better sound with the larger pipe and better cats, but you will also remain street legal.

Dan

 

[DixieOnMyMind59]

Ditto Jon, the subject went from obtaining a desired sound, to elliminating the cats, because other guys do it. Many of us tried to help, I suggested the best way to achieve the "sound." We weren't providing the answer required.

I was never asking how to obtain a desired sound (like a Mustang). I did that nearly a year ago in my thread I want to make my '99 5.0 Explorer sound like a 5.0 Mustang. . I was simply asking if it was possible to remove all four cats from my X. Now, after tons of research, i know what to do to make my 5.0 X sound like a 5.0 Mustang......
With the exception of having equal length pipes, i need to run a cat-less exhaust system into either an H-pipe or X-pipe, then run the pipes into my choice of mufflers then have them exit where i choose (out the back).

I have taken everyones opinions and advice into consideration. I am a very stubborn person and i will not take "NO" for an answer. The only way i can learn what works and what doesn't is if i do it myself and find out on my own. The ones that commented that have removed all 4 cats have testified to having their trucks running fine (with the exception of Mutineer having a CEL). This is enough reason for me to try it.

I know it is illegal not having any cats on my X and it is extremely loud - now you must take into consideration that i live in Mobile, Alabama - the southernest tip of Alabama and down here, we want the loudest exhaust systems we can get and most people down here could care less about a miniscule amount of air pollution...we don't even have emissions test (i don't even know what those are?)

Thanks to everyone who gave their opinions and shared their experiences on removing all 4 cats on a 5.0 Explorer. I only wanted to know if it was possible (with my engine still able to run) and what i needed to do to remove them.

If anyone has any more advice for me on this subject, please share it with me. I will not be getting my exhaust done for at least another 3 weeks because i am still paying off my new tires (which is a diff. story - i will be making a new thread about my new lift and tires soon).

Thanks Eveyrone,
Colton

 

[Mutineer]

No Prob.

I had an intermittant (sp?) EGR fault with my CEL also, and it may be that, after cleaning, re building the Vacuum and resetting the CEL and finally replacing the EGR valve, It went away, but this has been an issue. I dont have a scanner yet, so it may be that is what set my CEL.

Daniel

 

[DixieOnMyMind59]

Yea that's prob what it was.

Mutineer - What did you do about the O2 sensor located on the pre-cat on the pass. side?

Thanks,
Colton

 

[Mutineer]

I welded a "bung" Thread-nut onto the pipe for it. I do all my own fabrication. Im no expert, but I get the job done effectively.

 

[CDW6212R]

Sorry for all of your words, that doesn't change my accurate assessment. You asked about the cats, not because you would choose to keep them if that would be best, and serve the purpose. You wanted to remove them, for no reason given other than the sound of a "Mustang." Many of us responded correctly to you in saying that the cats are desirable, and legally required. We, including myself, spent quality time helping you to be able to achieve the "sound" without hurting the cats.

Bottom line, you wanted to cut them out, and you kept on until you got the answer that you wanted. I told you first thing that it was possible, and then suggested a smarter route, plus being legal. You should be more honest when you ask a loaded question. Good night,

 

[DixieOnMyMind59]

I wish a had access to a welder.

Mutineer-
Do you think that i could bring my X into most any exhaust shop with my two rear cats gone and ask them to remove my pre-cats and replace them with two high flow cats? Will they consider this legal? I would do this only because they would have to weld a bung on themselves. However, i don't like the idea of high flow cats when i could run no cats at all, i just cant weld myself a bung.

Do you still live in Alabama? If so, how far from Mobile?

Thanks,
Colton

 

[Turdle]

 

[FROADER]

I was never asking how to obtain a desired sound (like a Mustang).
Thanks Eveyrone,
Colton

It was the second sentence of this thread!!

I want to take off all four of my catalytic converters. Heres why....

Ok, im still trying to find that "Mustang Sound".
Thanks,
Colton

:scratch:

 

[MountaineerGreen]

Sorry for all of your words, that doesn't change my accurate assessment. You asked about the cats, not because you would choose to keep them if that would be best, and serve the purpose. You wanted to remove them, for no reason given other than the sound of a "Mustang." Many of us responded correctly to you in saying that the cats are desirable, and legally required. We, including myself, spent quality time helping you to be able to achieve the "sound" without hurting the cats.

Bottom line, you wanted to cut them out, and you kept on until you got the answer that you wanted. I told you first thing that it was possible, and then suggested a smarter route, plus being legal. You should be more honest when you ask a loaded question. Good night,

My thoughts exactly!

 

[Mutineer]

I cannot intelligently speak on what someone would do or not do, It depends on the shop.

Personnally, if you brought it into my shop I would not, simply because I know that the truck had them to begin with, and thats how the Federal Law reads: "All Original Emission Control Equipment" However, most shops will probably replace your primaries if you want them to.

I live NorthWest of Hunstville, about 8 miles from TN.

 

[AdvanceExpo]

Okay I'm sick of seeing a battle going back and forth. I had my cats cut on my 91 XLT and had 2 and a half inch pipe run from the headers into a magnaflow muffler. The muffler should have enough back pressure to help with what the cats had. It sounds mean with 2 and a half inch pipe and no cats. If you're worried about emissions find a shop outside of town that really doesn't care. Ask guys at auto stores because they usually know where to find these people because they deal with them on a regular basis like I do. It's your decision. BTW, you can order the dummy plugs for the oxygen sensors through JC Whitney. I saw them in the mag at one point within the past year. Goodluck. I know what kind of growl you want and I achieved the growl I want from my V6.

 

[MountaineerGreen]

Okay I'm sick of seeing a battle going back and forth. I had my cats cut on my 91 XLT and had 2 and a half inch pipe run from the headers into a magnaflow muffler. The muffler should have enough back pressure to help with what the cats had. It sounds mean with 2 and a half inch pipe and no cats. If you're worried about emissions find a shop outside of town that really doesn't care. Ask guys at auto stores because they usually know where to find these people because they deal with them on a regular basis like I do. It's your decision. BTW, you can order the dummy plugs for the oxygen sensors through JC Whitney. I saw them in the mag at one point within the past year. Goodluck. I know what kind of growl you want and I achieved the growl I want from my V6.

This is apples and oranges. Your first gen, non OBDII v6 is completely different than the truck in question.