FocusCanada Forums

I've got an MBRP exhaust and an OBX 4-1 header with cat eliminator pipe sitting in my place, waiting for install, and have 2 questions...

1) O2 cheater... will one be necessary with no cat? The bungs are there in the stock locations...

2) Flexpipe. The cat eliminator/downpipe appears to do away with the flexpipe. How necessary is this? I've had FWD cars in the past with no flex, and haven't had problems....

1 - as long as the sensors attach correctly and are introduced into the exhaust stream, you shouldn't have any grief.

2 - As long as everything clears everything else and doesn't rub, you ought to be fine.

1. If you're running a cat delete then YES you will need an MIL eliminator!

"Mil Eliminator
MIL eliminators prevent signals from the rear 02 sensors from unnecessarily triggering the Malfunction Indicator Light (MIL), commonly known as the ''check engine'' light, on all Zetec Focus equipped with off-road exhaust systems. The MIL Eliminators leave the ''check engine'' light fully operational for all other functions, so hte engine management processor can still send a warning signal if serious engine problems develop. MIL Eliminators are intended for off-road use only." - taken for somewhere i'd rather not advertise for <_<


2. That's gotta be one long ass header?! down pipe does away with the flexpipe? i've never seen that before.... Flex is after the cat section but before your "cat-back" section
Got any pics?

NOS2Go4Me,Jan 4 2006, 06:40 PM Wrote:1 - as long as the sensors attach correctly and are introduced into the exhaust stream, you shouldn't have any grief.

2 - As long as everything clears everything else and doesn't rub, you ought to be fine.
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Pretty much what i've assumed based on past experiences, but some people have been telling my otherwise....

As said prior yes you will need a MIL eliminator for the the second O2 sensor. I went without a MIL eliminator with my FS 4-1 header and did throw a CEL (the O2 cheater shipped after the header, and I didn't want to wait on the install).
As far as the flexpipe, i haven't seen any header combinations that do away with the flex pipe. But it would be a good idea to keep the flex pipe in to avoid any undue stress on any and all exhaust connections. less chance for a leaky exhaust with a flex pipe in place.
Do you have any pics of your header/downpipe combo, I'm sure many here could tell by looking at the pipes if it eliminates the flex or not

Your doing the install yourself or getting a shop to do it?

Your going to need the cheater.

I have seen the SVT header and it does not eliminate the flex pipe. It's just a smaller flex pipe.

that's what it looks like :)

The flex pipe would still be required after this header and before the MBRP exhaust. What this header eliminates is the stock cat. The flex starts after this header and snakes up over the front sub assembly and then joins to the aftermarket exhaust. You would not be able to attach this header directly to the exhaust without bumping in the the front assembly cross member and to go underneath it would make it lowest point between the tires and in danger of road damage.

I had a Meford™ senility moment. Yeah, you'll need the cheater.

Wow, lotsa responses. For the first time since I bought the car, I went under it with a flashlight after work.

This is actually the one I got....



So, what are my options for a flex? Not many aftermarket ones out there... I read something about the OEM flex being 2"?

Well for the record, thats a shorty header with an ORP (off road pipe). PM chromey, i think he just put one of those on his car not too long ago. He might have an answer for ya.

The standard aftermarket flex is 2 1/4", but you can get the 2 1/2" which gives you better flow.

Check with Mitch as he sells both.

Casper,Jan 4 2006, 09:40 PM Wrote:Wow, lotsa responses. For the first time since I bought the car, I went under it with a flashlight after work.

This is actually the one I got....



So, what are my options for a flex? Not many aftermarket ones out there... I read something about the OEM flex being 2"?
[right][snapback]163362[/snapback][/right]

Thats what i thought you were talking about. So as has been said it doesn't replace the flex pipe. As for replacement flex's as meford said Mitch (Zx3tuning) is a good hook up for that.

you have a great time installing that thing. :)



ok not to hijack this but is there enough room / possible to have a race header + universal cat + exhust?

nass,Jan 5 2006, 07:46 AM Wrote:ok not to hijack this but is there enough room / possible to have a race header + universal cat + exhust?
[right][snapback]163375[/snapback][/right]

That's what i plan on doing... as i just picked up the OBX 4-2-1 and have a cheater from when i had my ORP.

So i'm gonna see about a hi-flo cat weilded into my "cat-back" along with a bigger resonator or maybe just have a new section made :blink:

You just need to use a whole can of "QUIET! Damn kids!" on that thing, Gord :D

Trubendz will have any size felx pipe you will need. Thats where I got my 2.5"

http://www.trubendz.com

Flofocus,Jan 5 2006, 10:50 AM Wrote:Trubendz will have any size felx pipe you will need.  Thats where I got my 2.5"

http://www.trubendz.com
[right][snapback]163435[/snapback][/right]

The outlet on the header is 2.25", and Trubendz is more expensive than both New Edge and McNew's for a stainless unit.

Casper,Jan 5 2006, 07:51 PM Wrote:

Flofocus,Jan 5 2006, 10:50 AM Wrote:Trubendz will have any size felx pipe you will need.  Thats where I got my 2.5"

http://www.trubendz.com
[right][snapback]163435[/snapback][/right]

The outlet on the header is 2.25", and Trubendz is more expensive than both New Edge and McNew's for a stainless unit.
[right][snapback]163486[/snapback][/right]

Becuase it is a better unit! Now, truth be told, it probably won't matter alot with the equipment you have purchased. Your not going to be putting on a turbo anytime soon? with the OBX are you?
The 2.5" flex really allows more exhaust flow and frees up a little more hp. It's also a better quality piece and SS.
You pays for what you get.
But I wouldn't bother with the trubenz flex.