Evofusion Header, hi-flow CAT, Short/Long pipe question.

[Mark Reyes]

Be Gentle, I’m definitely a n00b, and I’ve searched the forums, but could not find this exact question I am going to ask, or perhaps the way that I word them.

I have a 2001 Elantra, I want to install new Headers and Catback, both from Evofusion.

http://www.evofusionusa.com/TeamSR/Hyundai/01elantra-header.html

http://www.evofusionusa.com/TeamSR/Hyundai/01elantra-exhaust.html

From what I’ve learned, this is how it should be installed to avoid a CEL.

Header, O2 Sensor, Flexpipe, CAT, 02 Sensor, Catback exhaust. Correct?

So my question is,

1. Why does the Evo Fusion Header have two O2 Sensors holes, if the first CAT is removed and the Second CAT is installed after the Flexpipe?

That would be Header, O2, Flexpipe, O2, CAT, Catback exhaust. That would cause a CEL.

Second question.

2. Can I put a CAT between the Header and Flexpipe?

So it would be, Header, O2, CAT, Flexpipe, O2, Carback Exhaust?

If so, the CATs I see don’t have flanges on them. http://www.andysautosport.com/hyundai/2001_2004_elantra/performance/exhaust/hi_flow_catalytic_converter/magnaflow/

They all seem to weld on.

So that leads to the third question, if the CATS don’t have Flanges to bolt on….
3. I get it welded on?

So it would be

Header, O2, Flexpipe, Cut flexpipe and “WELD” CAT between Flex Pipe before the O2 Bung, than Catback exhaust?

If welding is required, that leads to 4th and 5th question.
4. Which HI-Flow Cat should I get with the EvoFusion headers? and
5. Which Header do I get. The Short downpipe or the Long downpipe?

Thanks.
-Mark

[SilverElantra]

be careful what you buy from andy's

[kylemorg]

1. You could use a wideband O2 sensor in one bung and your regular O2 sensor in the other.

Don't have answers for you on the other #s

[lovemylantra]

dude evofusion delivery time sucks ... ive been waiting for over a month and half now for the catback exhaust and im still waiting for the top half of the intake cause they messed my order up so if you can avoid EF

[Killride]

thats funny... I got my header in 3 days....but missing the straight piece of pipe.... I got that piece 4 days later..... :bowdown:
I'm getting ready to install it! :D

[Mark Reyes]

KillRide,

When you get yours installed, can you share your results?

[lovemylantra]

whod you suck off for that to happen lol .. totally playing but damn man thats cause you probably live close to california

thats funny... I got my header in 3 days....but missing the straight piece of pipe.... I got that piece 4 days later..... :bowdown:
I'm getting ready to install it! :D

[Killride]

header was installed today.... so, before starting the car I reseted the computer ( diconected the battery) just in case ...dont want any codes:eek:
I feel the car has more output....but its way louder! I'm considering putting the silencer and if that doesnt work, I will try the catback..... so will see...
Besides the noise increase, I like it... looks good and fits well! :D:D:D

whod you suck off for that to happen lol .. totally playing but damn man thats cause you probably live close to california

:abovelol:... maybe its because I would drive over there and go postal !!:eek: jk...lol

[Silentwolf]

Seems like people dont LISTEN or ****ing read. If EF HAS the item IN STOCK, you will get it within the week (i've had this happen twice). If EF does not have the item in stock, it will take some time anywhere from a month to 6 months (for me it was 3 months which seems to be the norm for out of stock stuff) You just have to keep on them, i did one phone call a week.

[lovemylantra]

i live on the east coast theres no way i could drive to california lol ... and im always calling them and instant messaging them whenever i can so i guess im stuck waiting on it =(

[Mark Reyes]

So you removed both Cats from your system? Which one did you install, the Short Pipe or Long Pipe?

header was installed today.... so, before starting the car I reseted the computer ( diconected the battery) just in case ...dont want any codes:eek:
I feel the car has more output....but its way louder! I'm considering putting the silencer and if that doesnt work, I will try the catback..... so will see...
Besides the noise increase, I like it... looks good and fits well! :D:D:D



:abovelol:... maybe its because I would drive over there and go postal !!:eek: jk...lol

[Killride]

I drove the car yesterday....no cel..... I drove today to work and I got a CEL..... no what do I do? I thought the headers were designed to be bolt on and go!
any ideas? I cant use the search button on my cell phone :( seeing that yellow engine light makes my OCD's go nuts!!

[Munky]

Be Gentle, I’m definitely a n00b, and I’ve searched the forums, but could not find this exact question I am going to ask, or perhaps the way that I word them.

I have a 2001 Elantra, I want to install new Headers and Catback, both from Evofusion.

http://www.evofusionusa.com/TeamSR/Hyundai/01elantra-header.html

http://www.evofusionusa.com/TeamSR/Hyundai/01elantra-exhaust.html

From what I’ve learned, this is how it should be installed to avoid a CEL.

Header, O2 Sensor, Flexpipe, CAT, 02 Sensor, Catback exhaust. Correct?

So my question is,

1. Why does the Evo Fusion Header have two O2 Sensors holes, if the first CAT is removed and the Second CAT is installed after the Flexpipe?

That would be Header, O2, Flexpipe, O2, CAT, Catback exhaust. That would cause a CEL.

Second question.

2. Can I put a CAT between the Header and Flexpipe?

So it would be, Header, O2, CAT, Flexpipe, O2, Carback Exhaust?

If so, the CATs I see don’t have flanges on them. http://www.andysautosport.com/hyundai/2001_2004_elantra/performance/exhaust/hi_flow_catalytic_converter/magnaflow/

They all seem to weld on.

So that leads to the third question, if the CATS don’t have Flanges to bolt on….
3. I get it welded on?

So it would be

Header, O2, Flexpipe, Cut flexpipe and “WELD” CAT between Flex Pipe before the O2 Bung, than Catback exhaust?

If welding is required, that leads to 4th and 5th question.
4. Which HI-Flow Cat should I get with the EvoFusion headers? and
5. Which Header do I get. The Short downpipe or the Long downpipe?

Thanks.
-Mark

Man, I wish all n00bs were smart enough to ask detailed questions like this. If they were, we wouldn't have to hound them so much. ;)

Mark, make sure you check out this thread:

http://www.elantraxd.com/forums/showthread.php?t=26879

[Mark Reyes]

You need one of your O2 Sensors before the CAT and an O2 Sensor After your CAT.

so, IF you did the "Bolt on" it sounds like you had both your CATs removed. which means its sounds like you got the long pipe version and had it attached directly to the flange on the stock exhaust,

The EVO Header has the Bung for both O2 Sensors, but you need a CAT between them to avoid the CEL.

Which is why I opened the tread because I couldn't find any Bolt on CATs
and wanted to know if the replacement CAT had to be welded.

I drove the car yesterday....no cel..... I drove today to work and I got a CEL..... no what do I do? I thought the headers were designed to be bolt on and go!
any ideas? I cant use the search button on my cell phone :( seeing that yellow engine light makes my OCD's go nuts!!

heheh, yeah. I read that thread before I posted. I too was impressed by the Mad Photoshop Skillz....

but from what I gather so far, there are no Bolt on Cats to put between the Evo Header and the Flexpipe and therefore it will need to be welded in between the Evo "Long Pipe" and the second O2 sensor?

Man, I wish all n00bs were smart enough to ask detailed questions like this. If they were, we wouldn't have to hound them so much. ;)

Mark, make sure you check out this thread:

http://www.elantraxd.com/forums/showthread.php?t=26879

[BobMs_wht2k2]

I drove the car yesterday....no cel..... I drove today to work and I got a CEL..... no what do I do? I thought the headers were designed to be bolt on and go!
any ideas? I cant use the search button on my cell phone :( seeing that yellow engine light makes my OCD's go nuts!!

How did you install it? There is no "bolt on and go" when you remove half of your FEderally mandated Emissions equipment.

Oh, and good luck passing AZ emissions with no main cat. That should be fun.

[Mark Reyes]

If you remove the CAT, you can bolt on to the stock exhaust.


How did you install it? There is no "bolt on and go" when you remove half of your FEderally mandated Emissions equipment.

Oh, and good luck passing AZ emissions with no main cat. That should be fun.

[Codenomics]

I dont think AZ has emmissions laws, well not strict ones, try getting that thing smogged in Cali.

[Killride]

How did you install it? There is no "bolt on and go" when you remove half of your FEderally mandated Emissions equipment.

Oh, and good luck passing AZ emissions with no main cat. That should be fun.

.....I understand that.... but what should I do to eliminate the CEL problem? thats my question.... not wheather I pass the emissions test...

[Mark Reyes]

You need an O2 Sensor before your CAT and an O2 Sensor after your Cat.

.....I understand that.... but what should I do to eliminate the CEL problem? thats my question.... not wheather I pass the emissions test...

[BobMs_wht2k2]

Any visual inspection will be an automatic fail.

There is no guaranteed method. Your best bet is like has alread been stated above and throughout the entire site. If you have already done that, then you're up a creek. Its a 50/50 shot of being CEL-free.

[Killride]

the new header dont have room for the cat..... is prefab... Im going to reset the comp again and see what happens....hopefully it works.... otherwise what to do? :confused:

[Mark Reyes]

Well....

Thats one of the reasons I opened this thread.

It looks like the Long pipe needs to be cut, and the Cat Welded in. Much Like Evo says on their website.

But still, no one has answered one of my questions,:( Is there a BOLT ON Cat so there doesn't need to be a weld?

You are going to have to have a Cat installed, otherwise your CEL will come back. (there should be ways to lie to the computer, but I believe that it is more expensive)

the new header dont have room for the cat..... is prefab... Im going to reset the comp again and see what happens....hopefully it works.... otherwise what to do? :confused:

[KeWLKaT]

No bolt-on cats for our applications specifically.

And yes, you need a CAT as mentionned here: http://www.elantraxd.com/forums/showthread.php?t=26879

[Mark Reyes]

Thank you!:bowdown:

So that pretty much answers all the original questions, just last one. Any decent price specific Cat I should that works best with the EVO?

No bolt-on cats for our applications specifically.

And yes, you need a CAT as mentionned here: http://www.elantraxd.com/forums/showthread.php?t=26879

[BobMs_wht2k2]

the new header dont have room for the cat..... is prefab... Im going to reset the comp again and see what happens....hopefully it works.... otherwise what to do? :confused:

Seriously. . .read ALL the little stickies, and all the info given here and see if ytou can figure it out. You MUST have a cat between the sensors and there must be enough heat retained to keep them hot.

[lovemylantra]

or new york where i live ... youd prob get a fat a$$ ticket if they ever found out

I dont think AZ has emmissions laws, well not strict ones, try getting that thing smogged in Cali.

[BobMs_wht2k2]

I dont think AZ has emmissions laws, well not strict ones, try getting that thing smogged in Cali.

I can guarantee you that Tucson does. My brother in law had to turn his turbo Beetle back to stock every other year. . . It wasa 74.

[krodammi]

Oh, and good luck passing AZ emissions with no main cat. That should be fun.

AZ does have emissions and i know they aren't as strict as cali but my omni failed 10 times before i gave up and got the elantra so...

as far as your questions, i haven't got a clue so i'm going to wish you luck. personally i think its better to do it right the first time rather than trying to lie to the computer to make the cel go away (and i agree its annoying, i still can't get mine to go away) so props for doing your research first.

oh yeah and take lots of pics when you get it done ^_^

[tharptroy]

those prices at andy's autosport are about double most other online retailers. you should go to summit racing (if nowhere else) for any general automotive stuff like that.

[Killride]

funny thing is that I drove the car yesterday....lots of places and miles..... this morning I put the silencer on to make it quieter....and the CEL came on the moment I did!! I will remove it and reset the comp, will see...maybe I get lucky!!!:bowdown:

[BobMs_wht2k2]

If you have no cat between the sensors you will have a CEL. Period.




I don't know how else to explain it. . . I mean I'm seriously at a loss here. What else is there to explain?

[Mark Reyes]

:abovelol: I'm the N00b here and that was the first thing I said in my very first post. :D

If you have no cat between
the sensors you will have a CEL. Period.




I don't know how else to explain it. . . I mean I'm seriously at a loss here. What else is there to explain?

[BobMs_wht2k2]

I know . . . what he doesn't get is that it takes X-amount of drive cycles to trip the CEL. We have a massive leak in the A-pipe on the Accent and I can reset the ecu and drive it a day or even 2 before it comes back on.

[SilverElantra]

its a lost cause BOB-O just give it up and let the noobies who refuse to listen learn the hard way.

[Mark Reyes]

So no one has any Suggestions for a CAT that works good with Evo?

[BobMs_wht2k2]

So no one has any Suggestions for a CAT that works good with Evo?

Any decent, non-high flow cat would be fine. Infact, using the secondary cat from the elantra would likely work. Catco makes good OBDII cats (key there) for reasonable money.

Something to consider, the headers bleed a lot of heat from the engine to the cat, making the heating elements in the O2 sensors work a lot harder than necessary, possibly buning them out faster. I would consider wrapping your header (for under hood temps too) and the pipe to the cat. That way you retain as much heat as possible, cutting down on the chance of a CEL. Unfortunately, there is no guarantee.

[Mark Reyes]

Really? :confused:Why use a non-high flow instead of a high flow? (remember, I'm a n00b)

The current pipe on my exhaust is 2, the Header/Catback is 2.25, would using the stock Cat be a bottleneck?

Should I install the CAT as close to the header as possible? and the O2 sensor how far from the CAT should it be?

Any decent, non-high flow cat would be fine. Infact, using the secondary cat from the elantra would likely work. Catco makes good OBDII cats (key there) for reasonable money.

Something to consider, the headers bleed a lot of heat from the engine to the cat, making the heating elements in the O2 sensors work a lot harder than necessary, possibly buning them out faster. I would consider wrapping your header (for under hood temps too) and the pipe to the cat. That way you retain as much heat as possible, cutting down on the chance of a CEL. Unfortunately, there is no guarantee.

[SilverElantra]

use a non high flow so ur sensors dont get a false reading and throw a code anyways, thats what im dealing with now.

[Mark Reyes]

How about a California Legal Cat that will go on the Evo?

[KeWLKaT]

Well sorry guys but I have the following setup:

Hotshot header - (1st O2) Magnaflow High-flow cat - (2nd O2) - dynomax muffler

All piping is 2.5'' mandrel bent.

I have NEVER had a CEL. EVER. And that's with a high flow cat aswell. Frankly, Mark, the type of header doesn't make a difference. I used to have a dynomax cat before and I never got a CEL either. The reason I changed it is because the cat went awfully bad (see vid: http://youtube.com/watch?v=OYwCBzZ-9aM note, I was turbocharged back then).

So that means, go for your favorite Cat. Don't cheap out though, because you might get a nasty surprise (cause for failure on mine is still to be determined, ha).

P.S. Brilliant avatar, I was actually watching that movie again last weekend

God: What are you doing now?
King Arthur: Averting our eyes, oh Lord.
God: Well, don't. It's just like those miserable psalms, always so depressing. Now knock it off!

[03GT]

Any decent, non-high flow cat would be fine. Infact, using the secondary cat from the elantra would likely work. Catco makes good OBDII cats (key there) for reasonable money.

Something to consider, the headers bleed a lot of heat from the engine to the cat, making the heating elements in the O2 sensors work a lot harder than necessary, possibly buning them out faster. I would consider wrapping your header (for under hood temps too) and the pipe to the cat. That way you retain as much heat as possible, cutting down on the chance of a CEL. Unfortunately, there is no guarantee.

Making sure to keep that header wrap clean to avoid fires of course.

[BobMs_wht2k2]

nAH. . it's not a ford! :abovelol:

[Mark Reyes]

Yeah, that movie is classic. It took a while for me to figure out to add it.

I wish I could change my name too, I seem to be the only moron that put their real name instead of a handle.... :hand:

so, being that I WON'T buy a $50 cat :D, and the Evo is 2.25, than this one should work out? http://www.andysautosport.com/hyundai/2001_2004_elantra/performance/exhaust/hi_flow_catalytic_converter/magnaflow/magf00011632.html

Well sorry guys but I have the following setup:

Hotshot header - (1st O2) Magnaflow High-flow cat - (2nd O2) - dynomax muffler

All piping is 2.5'' mandrel bent.

I have NEVER had a CEL. EVER. And that's with a high flow cat aswell. Frankly, Mark, the type of header doesn't make a difference. I used to have a dynomax cat before and I never got a CEL either. The reason I changed it is because the cat went awfully bad (see vid: http://youtube.com/watch?v=OYwCBzZ-9aM note, I was turbocharged back then).

So that means, go for your favorite Cat. Don't cheap out though, because you might get a nasty surprise (cause for failure on mine is still to be determined, ha).

P.S. Brilliant avatar, I was actually watching that movie again last weekend

God: What are you doing now?
King Arthur: Averting our eyes, oh Lord.
God: Well, don't. It's just like those miserable psalms, always so depressing. Now knock it off!

[03GT]

nAH. . it's not a ford! :abovelol:

http://www.youtube.com/watch?v=2iIDvYjifmc&NR=1

listen for the ricer a-hole racing by like he's tom cruise in days of thunder or some chit.