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· Mad Scientist
94 scepter coupe
Joined
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5,552 Posts
Discussion Starter · #1 · (Edited)
PIPE

Your cat is a restriction on your exhaust system

solution: put in a high flow cat...but wait your broke like me...what do you do?

weld your own

materials:
2.5 inch pipe about 2 feet
header paint of your choice

tools:
welder tig/mig/arc/torch(i have a mig)
14mm wrenches and socket maybe even that tool that gets stripped nuts/bolts out
an angle grinder with a cut off wheel x2

1. jack the car up and secure it in place.
2. remove the cat from the car.
3. lay the cat next to the pipe to get the approximate length the pipe should be
ex:


4.now that you cut the pipe to what you need. cut the flanges off the cat.
5.bolt the flanges back on the cars exhaust system.
6.try to fit the pipe in place if need be cut it down a little.
7. now here comes the welding. tac it in place in several places.
8. remove it from the car and weld all around to keep it secure and leak free.
ex:

9. when your satisfied paint it if you wish (all i had was gold paint)
ex:


10. put it back on the car and tighten it using new bolts.
11. turn the car on to make sure there are no leaks.
ex:

12. lower car and go for a test run.

my car has a nice hollow tone to it like a g35 or murano with a borla exhaust. no raspyness and if need be i can replace the cat.

my car spec:
1994 toyota camry v6se 1mzfe 6coilpacks SRI two cheapy mufflers that are about 24inches each.


edit:
as of the moment my check engine light is on but it's for other reasons but yeah it will throw another code.
 

· Nostalgia Member
Joined
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7,748 Posts
its gonna need an O2 sensor bung, but yeah .... thats a DIY Test Pipe for ya (not really hi-flow cat, since its not a catalytic converter at all)

oh, and none of you guys with visual smog inspections can do this, unless youre going to have a 2nd set of flanges so u can put the cat back on :(
 

· Nostalgia Member
Joined
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7,748 Posts
why would i need an o2 sensor bung? or are you talking about if i wany to put a wide band o2 sensor. i can do that later.
the down stream sensor in actually on teh cat-back, after the cat section. so he should be good but it would still prolly throw a code.
i was thinkin the O2 was on the tail-end of the cat, but you still have that part attached as bigbird has informed me :thumbup:

but yeah, it would be nice to have wideband (or even narrowband if youre poor)
 

· Official TN PimP
Joined
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943 Posts
why would i need an o2 sensor bung? or are you talking about if i wany to put a wide band o2 sensor. i can do that later.


within 50 to 100 miles, ur likely to get a code for o2 sensor bank 1 sensor 2 malfunction.


if u get this code, which u will....u need to do one of three things..


get a REAL cat on there...

Do the Spark plug fouler mod...

or get a o2 simulator from www.urdusa.com
 

· Young Toyota Tech
00camry98eclipsegsx
Joined
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129 Posts
agreed but what year is the car we are talking about? 94 might just get away with it



quote=Dawgz;2069299]within 50 to 100 miles, ur likely to get a code for o2 sensor bank 1 sensor 2 malfunction.


if u get this code, which u will....u need to do one of three things..


get a REAL cat on there...

Do the Spark plug fouler mod...

or get a o2 simulator from www.urdusa.com[/quote]
 

· Simpsons fan since 89'
1993 Lexus SC300
Joined
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1,634 Posts
Nice write up!

A mig welder is a great investment.
 

· TN Pussy Man
Camry
Joined
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13,120 Posts
lol

gino, you make it look so easy. which it is. if you can weld. which most of us can't. or can, but don't have a welder. lol.

but I'm adding this to the DIY stickie :thumbup:
 

· Registered
1995 Camry LE Wagon
Joined
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5,730 Posts
Unless you've done a before and after dyno test you have not proved that removing the CAT did anything for HP/torque. And where are you going anyway in such a hurry? But what you have done is think that air pollution is not your problem just other people's problem.
Here is a way to get better flow (if you can prove you need it) AND stay legal and still be a responsible citizen.
http://www.randomtechnology.com/
 

· I HAS BOOST!!!
94 Camry SE V6 Coup
Joined
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10,891 Posts
Unless you've done a before and after dyno test you have not proved that removing the CAT did anything for HP/torque. And where are you going anyway in such a hurry? But what you have done is think that air pollution is not your problem just other people's problem.
Here is a way to get better flow (if you can prove you need it) AND stay legal and still be a responsible citizen.
http://www.randomtechnology.com/
removing the cat or putting in a highflow cat does ad power. he dont need a dyno to prove that, just simple physics. i do agree it would be polluting more.
 

· How hard can it be?
1996 Camry LE
Joined
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1,788 Posts
I guess it might be different outside of Cali., but my O2 sensors (5sfe) are before and after the manifold (upstream) converter. The downstream converter has no O2 sensors on my car. Maybe I could throw in a test pipe from ebay, and swap the oem converter back in for smog checks.
 

· Nostalgia Member
Joined
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7,748 Posts
doesnt Broward County still have smog requirements? .... its been so long, but i do believe that you need a cat :lol:
 

· Registered
1995 Camry LE Wagon
Joined
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5,730 Posts

· I HAS BOOST!!!
94 Camry SE V6 Coup
Joined
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10,891 Posts
air restriction is the concept. if ur trying to force gases through the dense honey comb of a cat, the material is going to restrict how easily the exhaust can flow through it. removing it will allow the gasses to move unobstructed. that increase in flow allows the engine, on the exhaust stroke, to more eaisly and completly push the exhaust gasses out of the cylinder. that translates in to reduced parasitic loss and a cleaner charge on the intake stroke. the same concept will apply to the K&N airfilter we were not talking about. it will result in positive gains but minimal on these cars.

me personally, id rather just put in a highfolw cat, which would flow very well, and not have to mess with the o2 problem or add to polution. but this is for people who dont want or cant do that.

if u want numbers feel free to go and prove me wrong but im confident enough in my statment to know that removing the cat would free up some power, how much, that i dont know.
 
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