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Clearing Catalytic Converter; Need help to clean cat
Topic Started: May 12 2011, 10:51 PM (5,984 Views)
climbinghalfdome
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MPG OCD

dayle1960
May 14 2011, 02:10 PM
The best way to clean a cat is to chop it off and run a straight pipe.

Posted Image

Works for me, if I get ambitious enough I'll just solder it back on.
Whats the effect on your MPG if you remove the CAT and straight pipe it? I'm thinking because of changes in back pressure I'd think your MPG would go down.
Kevin
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mcmancuso
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Almost none to none, the cat is not responsible for back pressure, as it is designed the cat should be free flowing, and the pipe diameter is the major restriction. I have had no loss in mileage from removing the cat on either of my cars. later model metros use a rear O2, which monitors cat efficiency, but it dies not have fuel trim authority, its just there to watch.
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Tofuball
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Strange Mechanic

Back pressure is almost never good.
Velocity is good.

Cats are all rather restrictive.
MPG almost always goes up.
MPG AWALYS goes up with supporting mods after removing a cat.

For offroading purposes only, of course.
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mwebb
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FOG

Tofuball
May 28 2011, 08:27 AM
Back pressure is almost never good.
Velocity is good.

Cats are all rather restrictive.
MPG almost always goes up.
MPG AWALYS goes up with supporting mods after removing a cat.

For offroading purposes only, of course.
Posted Image
i removed my cat to see
and
it makes no difference at all in fuel economy , or felt power .
and
there is no p0420 and the cat monitor still runs ! ?

on my G10 with the 3tech economy cam

did i measure calculated load at WOT before and after ... ?
probably
i will have to dig through the files

best performance enhancement so far ..
remove the 3tech+10 cam wheel .
Posted Image

because with the 3tech +10 cam wheel and the 3tech economy cam
EVC is at
334 degrees ATDC and some exhaust gases can not escape
Posted Image see above
EVC for stock cam is 366 degrees ATDC , there is valve over lap ! big difference all exhaust gases can escape .

you can NOT solder a Catalytic converter any better than you can throw a potato chip .
Edited by mwebb, May 29 2011, 12:05 AM.
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Coche Blanco
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Troll Certified

I'm so glad mwebb is back.
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HatchJunki
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Member
[ *  *  * ]
Still beating that dead horse...
Edited by HatchJunki, May 31 2011, 07:02 PM.
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mwebb
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FOG

HatchJunki
May 31 2011, 06:54 PM
Still beating that dead horse...
the horse is alive and well

flatlander
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climbinghalfdome
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MPG OCD

mwebb
May 29 2011, 12:01 AM
Tofuball
May 28 2011, 08:27 AM
Back pressure is almost never good.
Velocity is good.
Posted Image

on my G10 with the 3tech economy cam
best performance enhancement so far ..
remove the 3tech+10 cam wheel.
with the 3tech +10 cam wheel and the 3tech economy cam
EVC is at



Wait, wait, wait. Are you suggesting that the economy cam and the +10 advanced timing sprocket conflict with each other? If so Which would you use? I've read you post several times and still can't rap my noodle around it. Any way to break it down on smaller brain terms?
Kevin
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gamefoo21
2 Swifts n a Turbo Sprint

*le sigh*

The most restrictive thing on the entire exhaust system underneath that car assuming it has the stock system...

is not the CAT... the cat is the same one used on the DOHC 1.3L...

Simple garden hose test...

Cat flowed the garden hose without issue...

The resonator on the other hand... it back it all the way up the pipe, within a few seconds and I had overflow.

Silly people gut cats, smart peoples go out and buy a $60 Magnaflow, and ditch the rest of the system, while realizing that this blue marble is a closed system, and even a highflow cat, will reduce the poison coming out of the tail pipe by a huge amount. :O
Edited by gamefoo21, Jun 28 2011, 03:18 AM.
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99metro
putt-putt

My cat has a huge hole through it only because it was a cheap Catco replacement. Never bothered replacing it. I plan on putting in a straight pipe in it's place one of these days - but it essentially already is. Didn't hurt fuel economy and no idiot light.

Resonator - definitely.
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Tofuball
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Strange Mechanic

gamefoo21
Jun 28 2011, 03:17 AM
*le sigh*

The most restrictive thing on the entire exhaust system underneath that car assuming it has the stock system...

is not the CAT... the cat is the same one used on the DOHC 1.3L...

Simple garden hose test...

Cat flowed the garden hose without issue...

The resonator on the other hand... it back it all the way up the pipe, within a few seconds and I had overflow.

Silly people gut cats, smart peoples go out and buy a $60 Magnaflow, and ditch the rest of the system, while realizing that this blue marble is a closed system, and even a highflow cat, will reduce the poison coming out of the tail pipe by a huge amount. :O
Yes, the stock muffler is more restrictive then the stock cat (at least the ones I had)

Unless something has changed recently, a cat produces 5 to 7 times more pollution to create then it will ever clean up.

So I never advocate breaking a perfectly good cat. Chop it off and save it if you have to.

Unfortunately to keep the cat living a long life, you have to keep your combustion temps\ratios in a certain range. On a lot of cars that involves a ton of extra gasoline dumped in . . . The restriction of the cat is probably negligible on our cars compared to the compromises that had to be made in regular running conditions to preserve the cat.

However the Geo Metro is much less affected by that then say, an RX-7.
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seattlegeoboy
Fresh Fish
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hey guys where do you put the seafoam exactly? im sort of new to this but understand the concept and parts pretty well. i have pictures and instructions with my chiltons book. Thanks!
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Metromightymouse
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Powdercoat Wizard

Read this thread and decide for yourself whether you want to use it in your engine. What is described in this thread is pouring it directly into the exhaust, probably right after the manifold, to try to clean out restriction or build up in the catalytic converter. I have rather serious doubts about its efficacy since it wouldn't likely reach the upper part of the cat.
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seattlegeoboy
Fresh Fish
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So basically, what youre telling me is i have to disconnect the pipe from the exhaust manifold, to get the seafoam in there? What i was trying to avoid is taking off, otherwise i might as well just buy a new cat which goes for around 80.
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Metromightymouse
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Powdercoat Wizard

Based on my understanding of what was posted here, yes, you have to open the exhaust somewhere before the cat.
Are you sure the Cat has an issue?
Also, I would only use the Chilton for reference and photos and rely more on a factory service manual (FSM), which should be accessible in the manual section of the forum.
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