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QwikKota
Dodge Dakota
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9/02/2003
18:05:55
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 Subject: Anyone gutted the Cats? 01+ 4.7L How to?
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I want to install some headers and at the same time gut my pre-cats. Pretty sure there is no flange after the cat downstream. Only way I see doing this is removing the headers, bashing up the cat material and blowing all out down the pipes and out my cutout.
I will run a 3rd cat to be emissions friendly, but want to gain some top end power. Anyone have any experience with this method?? I don't want to screw up anything. The replacement for the Y is around $750. I think if I leave the upstream 02 in and plug the downstreams I will be safe from tripping MIL lights. Going to wrap the Downstream O2's in foil and tie them up securely. Sound good??
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Rob454
Dodge Dakota
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9/02/2003
22:56:19
|  RE: Anyone gutted the Cats? 01+ 4.7L How to?
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personally I wouldnt screw around with the pre cats. they seem to be integrated with the O2 sensors. I do know placement of the O2 sensors is a huge part of the smog system and overall computer metering of the fuel and Os in the exhaust. I think youre gonan mess up the way the vehicle runs.
My 00 dakota has 2 pre cats and one cat in the normal area under the passenger side exhaust.
Rob
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2003black
Dodge Dakota
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9/02/2003
23:01:28
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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people are gaining some better performance in the 4K plus area by just cutting off the third cat. Better mileage too.
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QwikKota
Dodge Dakota
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9/02/2003
23:04:55
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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I understand what you are saying, fuel metering and all. However this is how almost all of the R/T guys do their setups. Get rid of the pre cats and sim or zip tie the rear O2's. How can it be any different on the 4.7L?
I have a 3rd cat and plan on keeping it, cutout before it if I want to bypass. Cat makes my Borla muffler sound awesome, other wise it would be raspy and much louder.
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Rob454
Dodge Dakota
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9/03/2003
21:07:28
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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I didnt think the RTs had 3 cats. I thought they only had the normal cat under the passanger side.
I may be wrong. Do you really want your new truck to spew out black smoke? thats liek taking a 25000$ truck and turning it into a 1000$ gardening truck. There are other ways to gain power without turning your truck into a UPS delivery van.
Just my opinion. im sure 20 guys on this board will jump on this and tell you its ok.
I personally wouldnt go cutting emissions equipment
Rob
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rtdkota
R/T
9/03/2003
21:54:00
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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Yeah, QwikKota-- shame on you for making a vehicle spew black smoke.
LOL.
'00 with Precats? Must be a CA. 4.7 thing, as the 5.9Ls don't have precats.
Sam
www.socaldakota.com
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nakonap
Dodge Dakota
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9/03/2003
22:52:11
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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hey if you are going to do it this is what i did with my 96 mustang.
i took and had to get new cats so i just had a new y made with only the 2 primary cats left the pre cats out and had the sensors installed acourdingly
nakonap
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dak4.7
Dodge Dakota
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9/04/2003
02:48:12
|  RE: Anyone gutted the Cats? 01+ 4.7L How to?
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HEY, ive got a 2001 quadcab 4.7 and removed all the cats. It runs better believe me. All you havew to get is a o2 sim for the downstream o2 sensors,$119 from jegs. It runs good even without sim just sets a mil light in dash. I will have a Duner style turbo setup soon.
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QwikKota
Dodge Dakota
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9/04/2003
09:20:39
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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Sam don't be a goof, you know I have a 2002. And all 2001 up R/T's have pre-cats!
Dak4.7 how did you replace the y-pipe on your truck? I was thinking about getting some collector extensions from Jegs or summit. They have the 3 hole collector flange with a 15" pipe welded on them. They are about $25 or so each. Then I could take those to a muffler shop, have them flare the pipes out to slip over the stock y-pipe size. Then cut out the cats so that if I had to replace them I wouldn't damage them as Sam suggested to me on the phone. I would just have to get an O2 bung welded in on each and tie up the downstream O2 in foil and what not.
And Rob454, let me know when you learn how engines work. I am keeping the 3rd cat, its a high flow, that's plenty to satisfy you tree huggers. Black smoke is for diesels, silly rabbit!
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Rob454
Dodge Dakota
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9/04/2003
21:20:33
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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KwikKoda
All Im saying is why remove something that helps keep the air cleaner? another thing How do you guys pass a visual smog check without any cats? you guys must not be in California and if you are the smog tech must be a complete moron to pass you.
I had to take off a the cat on my work truck ( Dodge Ram) and I drove it to the muffler shop and everytime I pressed on the gas it made a black smoke trail.
I know how engines work. I may not know every small little bitty detail about them. Im not a tree hugger but I do like breathing.
I can understand wanting more power out of your truck, but just taking stuff off and polluting IMO is not the way to do it.
Im sure you guys will post on here how its better and bla bla bla.
Everyone is entitled to their opinion I guess
Rob
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nawoj
Dodge Dakota
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9/04/2003
22:36:51
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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gutting a cat is not the prefered method, it causes turbulance in the pipe...
imagine exhaust gases flowing down a pipe, nice and smooth, then it suddenly is expelled into a cannister, then back into a pipe and how much turbulance that makes.
sure it will decrease the restriction, but if your gonna do it, might as well do it right...
stick a pipe in there... cut and weld.
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QwikKota
Dodge Dakota
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9/05/2003
09:16:04
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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Yeah, I am probably going to just swap them out for a test pipe when I get some more time and money. Its just hard to find a shop that will do it. The R/T guys run straight pipe there and keep the upstream O2, no codes pop or anything. I have a 3rd cat and am keeping it, the 4.7L is not a huge emmissions problem and 1 main cat should suffice. All the 2000 4.7L's had was one cat and they pass emmissions. In Texas the inspection is rarely visual, and if they do look up under there they will see the main cat. As long as no codes show up on an post-1995 vehicle, you pass, there is no sniffer.
Rob if your work truck was leaving black smoke then the motor had bigger problems than exhaust issues. More than likely you had some bad valve guide seals and were burning oil, or something similar.
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Yup
Dodge Dakota
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9/05/2003
15:47:20
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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And thats probably what killed his cat.
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QwikKota
Dodge Dakota
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9/05/2003
15:57:15
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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Exactly, I forgot to add that. A lot of unburnt fuel will kill a kitkat too. If you turn the key to start to shut off the computer it makes the engine run rich, dumps a lot of fuel down the exhaust. Kills the governor tho ;-)
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mrsbaddakota
Dodge Dakota
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9/07/2003
03:22:26
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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I have a question. What will I gain besides more noise on my 4.7 by removing the stock muffer and replacing it with a 2 !/2" Glasspak?
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qwikkota
Dodge Dakota
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9/07/2003
13:12:02
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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You will gain more power by replacing the stocker with a thru flow design muffler. I have a Borla Pro XS 3" muffler on my truck and I get nothing but complements. Just about everybody thinks it sounds awesome. Not sure what a glasspack would sound like on this motor, but I doubt it would be a very desireable exhaust note.
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mrsbaddakota
Dodge Dakota
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9/07/2003
18:24:25
| RE: Anyone gutted the Cats? 01+ 4.7L How to?
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qwikkota,
Thank You for the input, I'm more interested in gas MPG, & Performance than sound.
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