No Cat... is this safe ?

[jononioo]

i took my catylic converter off my 96 s14 and i was wondering if this safe for my engine. Some ppl are telling me that its fine for it and others are saying its bad for my engine b/c i have no back pressre so my valves will fry b/c they won't open and close when they should... will a knoledgable member of zilvia.net set the record straight!!!

[wootwoot]

the only things its going to hurt is the air and your wallet if they catch you without it

[S14DB]

what did you put in place of your cat?

[kingsol]

you'll be cool, but you have a test pipe right?

[orion::S14]

It won't "burn your valves"...that's an old BS rumor.

(That *could* happen if you ran NO header, so open valves to the atmosphere...but NOT in your situation)

And you don't need backpressure...that's also a myth.

So...with all that said:

It's best to replace the cat with a test pipe or a high-flow...having just that big, empty area in your exhaust will slow you down. It needs to be smooth flow for high velocity...that is what's important. Not backpressure.

And for what it's worth: SCC gained HP and TQ by adding a high-flow cat to their project 240SX...

- Brian

[S14DB]

This a 96 so the cat is in the downpipe not in the S13 location. That's just a holow shell.

[PinkPanther]

You're going to screw up the rich/lean cycles programmed into your ecu, b/c there is no change in 02 between the 2 sensors now. You might want to get a cat simulator so that your ecu doesn't throw a catylist failure code for im240 emissions testing(if you are required to do it).
The only reason you would NEED backpressure is if you have a positive backpressure transducer in your EGR system, but i'm unsure if the 240 has it or not. Have fun spitting hydrocarbons everywhere.

[S14DB]

I have a OBX header which gets rid of the cat in S14's. My cat code get's throwen every 500+miles. Not a major pain. I still would like to know how he got rid of his cat.

[jononioo]

what did you put in place of your cat?

nothing... there is just a gap between my cat and the rest of my exhaust sysetm

you'll be cool, but you have a test pipe right?

nope... not yet at least... will it still be loud with a test pipe...i kinda like it loud

.... im240 emissions testing(if you are required to do it).

I still would like to know how he got rid of his cat.

..well, i just unbolted it from my exhaust... i don't get emmisssion tested where i live so the cat is just sitting in my garage.

[kingsol]

hahaha you're crazy, your car will be stupid loud!

[PinkPanther]

I dare you to take your car to cali and drive it around San Diego and LA

[jononioo]

no thanks man, i prefer not being behind bars

[mr_240sx]

Originally Posted by kingsol

hahaha you're crazy, your car will be stupid loud!

im running my sr20det with an apexi downpipe and apex'i n1 cat-back with no cat! its not any louder then the ka24 with a cat!

PS: ive had some people telling me that when they were following me that when i would shift, there would be a blue flame shoot out from the exhaust about 3 inches out !!!

[Var]

Originally Posted by jononioo

nothing... there is just a gap between my cat and the rest of my exhaust sysetm

so you're running open header? right?

[S14DB]

Originally Posted by jononioo

nothing... there is just a gap between my cat and the rest of my exhaust sysetm

nope... not yet at least... will it still be loud with a test pipe...i kinda like it loud




..well, i just unbolted it from my exhaust... i don't get emmisssion tested where i live so the cat is just sitting in my garage.

so, you took out the fake cat or the real cat?

This is a fake cat on the S14's

[HyperTek]

whatever u do.. maybe just disconnect the battery for an hour (resets ECU) so it will just reprogram to whatever it reads and adjust blah blah?? I know I said that a million times to people who installed intakes at my previous job and it works, so maybe this would clear up some of that sensor bs...

[kingsol]

Originally Posted by mr_240sx

im running my sr20det with an apexi downpipe and apex'i n1 cat-back with no cat! its not any louder then the ka24 with a cat!

PS: ive had some people telling me that when they were following me that when i would shift, there would be a blue flame shoot out from the exhaust about 3 inches out !!!

if you have no cat and nothing replacing it, you're running an open header, which means the rest of your piping, supposedly after the cat, is useless. i've driven to the exhaust shop once with an open header... it really is super hekka duper loud.

[mr_240sx]

Originally Posted by kingsol

if you have no cat and nothing replacing it, you're running an open header, which means the rest of your piping, supposedly after the cat, is useless. i've driven to the exhaust shop once with an open header... it really is super hekka duper loud.

well where the cat used to be, i welded in a 3inch pipe so its pretty much a 3inch straight pipe!

[CA20Guy]

you'll just lose some backpressure and get alot louder. cause your losing backpressure your power will decrease slightly ....but not much...

[Doriftomodachi]

If you plan to stay with the ka with no cat but you want more power get the hotshot header. It gets rid of all cats (real and fake), flows smoothly and you will notice nice hp and torque gains.

[95Blue240sx]

Originally Posted by S14DB

I have a OBX header which gets rid of the cat in S14's. My cat code get's throwen every 500+miles. Not a major pain. I still would like to know how he got rid of his cat.

I use to run the HS header in my S14 and it never threw a code. It's the same for the guy i sold it to.

[wootwoot]

hp is not lost because of a lack of back pressure, and for some reason, the ka operates rather well in n/a form with no backpressure. in any situation back pressure does not make you lose power, it just ups your power band slightly, so technically you lose torque

[S14DB]

Originally Posted by 95Blue240sx

I use to run the HS header in my S14 and it never threw a code. It's the same for the guy i sold it to.

Since I got the right map sensor on my car I have not thrown it. It's been over 600miles. When I was throwing the map code the cat code would throw. they could have been related.

Originally Posted by mr_240sx

well where the cat used to be, i welded in a 3inch pipe so its pretty much a 3inch straight pipe!

was this a angled pipe. Cause the cat is in the DP and makes a 45 degree turn.

The DP with the cat is on the left. A test pipe in place of the fake cat is in the center and the cat back is on the right(black).

[mr_240sx]

Originally Posted by S14DB

Since I got the right map sensor on my car I have not thrown it. It's been over 600miles. When I was throwing the map code the cat code would throw. they could have been related.

was this a angled pipe. Cause the cat is in the DP and makes a 45 degree turn.

The DP with the cat is on the left. A test pipe in place of the fake cat is in the center and the cat back is on the right(black).

it looks something similar to that picture except for my downpipe connects to the new pipe completely straight and there are no bends in the pipe except for in the cat-back, which is a slight bend.

[S14DB]

you do realize that what was in the place of the center pipe is Hollow?

[theicecreamdan]

no its not safe, you will kill all the plants and animals, all for a 2hp gain,

[ThatGuy]

As long as you didn't remove the Muffler Bearings you should be ok.

[9524tee]

i have a hotshot header , which takes the "active cat" out , first off , and i have a enjukuracing testpipe , which replaced the dummy cat , and an hks hi power cat-back , its loud , and spits flames , but my check engine light has never come on , and it is so much quicker in the high end past 4k rpm,s ... hope that helps .

[CA20Guy]

Originally Posted by theicecreamdan

no its not safe, you will kill all the plants and animals, all for a 2hp gain,

.....save the planet.

[Dream240]

Originally Posted by Doriftomodachi

If you plan to stay with the ka with no cat but you want more power get the hotshot header. It gets rid of all cats (real and fake), flows smoothly and you will notice nice hp and torque gains.

Not true, the HS header only removes the exhaust manifold and stock cat, not the hollow fake cat. You will need the test pipe mentioned above.

I went with the HS header, Random Technologies high flow cat, and the Apex N1 dual. I don't like the High flow-to-exhaust portion casue of the size differences. Eventually i'm gonna change exhausts to a Greddy for noise. Oh yeah and get new gaskets and mounting bolts taht way it will bolt up easily and clean.