Catalytic Converters
04-22-2010, 06:04 PM
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Catalytic Converters Hey All,
I was getting SES lights for faulty O2's so I went ahead and replaced all 4 of them. Everything was fine for about 2 weeks, but now I am getting an SES light from my Cat's
I guess I shouldn't be surprised since the O2's and Cat's were all stock. So......now I am checking to see if anybody on here has reasonably priced Cat's they would like to part with???
I was getting SES lights for faulty O2's so I went ahead and replaced all 4 of them. Everything was fine for about 2 weeks, but now I am getting an SES light from my Cat's
I guess I shouldn't be surprised since the O2's and Cat's were all stock. So......now I am checking to see if anybody on here has reasonably priced Cat's they would like to part with??? 
04-23-2010, 06:19 PM
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Do not "gut" the cats. There are several reasons not to do so. Especially if the engine is still normally aspirated. They are as follows:
The major one being that the current generation of catalyst elements are not very restrictive at all. In fact, they actually work like a tuned collector on normally aspirated engine. As the exhaust gases pass through them, they act like a check valve for exhaust flow. As the exhaust valve closes, momentum causes the gases to continue to travel through the exhaust system. This is plenty of energy to pass through the cats. This causes a vacuum to build up between the exhaust valves and the catalytic converter. The energy required to pull the gases back through the element can't build fast enough to work before the next exhaust valve opens. When that next exhaust valve opens, it is opening to a vacuum environment which helps to PULL the gases out of the cylinder due to what is called "scavenging effect". This translates into more power as the piston now does not have to do all the work to evacuate the cylinder of spent combustion gases.
Second, if you were to remove them, you would definitely want to use a cat removal pipe. The chamber left after you would "gut" the cat is actually worse at losing energy than a catalytic element (understand I mean element designs after around 1990). This is because as the gases enter the empty chamber, exhaust velocity slows down. As it then regroups to enter back into the exhaust piping, it does not have the energy it did before, therefore it "stacks", causing backpressure. This backpressure now works against the flow of spent gases out of the cylinder when the exhaust valve opens, causing the piston to do all the work. Now, energy is being wasted for gas removal that could otherwise be used to turn the crankshaft.
My recommendation would be to leave the cats alone and concentrate of every other part of the airflow system. After all else is done, come back to them, and if not using a high flow catalytic converter, then use a cat-delete pipe.
Shawn @ Street Sports
.......don't think I am going to gut mine.
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04-27-2010, 03:59 PM
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If you want to pass visual inspection if you are worried about that, then:
http://www.siliconeintakes.com/produ...4df56b3ffd94f0
http://www.siliconeintakes.com/produ...4df56b3ffd94f0
05-04-2010, 09:09 AM
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^^^
x2 i did mine last yr before i put her way for the winter. It was either that, or i spend $1,500 on some Kooks and a catted-y (NJ). If i had to BUY the cats, i wouldnt buy 2 not just one, they're $500 a piece, and i would not dump that into stock ****. lol.
If it's free, its for me!
x2 i did mine last yr before i put her way for the winter. It was either that, or i spend $1,500 on some Kooks and a catted-y (NJ). If i had to BUY the cats, i wouldnt buy 2 not just one, they're $500 a piece, and i would not dump that into stock ****. lol.
If it's free, its for me!
