Compatible header w/ MP3p5; Focus or Probe 2.0

ARD MP5

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Contributor
Guys, I need some real life experience here.

Does anyone know for sure if it will work? I have a couple companies that produce the header for a focus? Do the focus' have a precat as well? In that case, does the header include a downpipe or is it connected?

How about the probe? What kind of minor mods need to be done? I can get all of you a killer deal on the Bosal if you guys can confirm s*** with me.

Thanks in advance,
Rishie

I have a few companies that will release headers by the beginning of the year sometime specific for our app, but I can't wait.
 
A guy named brian has put the header from the mid 90's probe on the MP3. He told me all you have to do is some mod's on the flange. He says it's not too hard. But he said the check engine light will come on b/c it takes out the 1st cat and the O2 sensors. But he also said that if you relocate the O2 sensors to the front and rear of the second cat it will work fine. I think I'm going to save for a header that fits though. I think it will give our MP3's the most bang for the buck. The instalation of our CAI's and only getting about 2 to 3 hp proves this. If that cat wasn't there, the hp gains would have been more with the addition of a CAI.
 
Well, Derrick @ Corksport told me that the header off of the 93-96 MX-6 will work for our cars. It removes the primary cat, therefore he told me that the engine light will come on if you leave the o2 sensors out. But can't we just extend the o2 sensor wires back to the second cat and splice them in together there, so both o2 sensors read off of one cat?

I don't see why not.

BTW...The MX-6 header on Corksport is only $329.00 bucks.

[ 12-01-2001: Message edited by: MP3-Owner ]
 
The MP3/MP5 should be the same as other ODBII cars I've done so you should be able to remove one or both cats without tripping the check engine light. To do this both O2 sensors have to be in the exhaust stream and there is a small wiring modification done to the second sensor. When I can access my webpage I'll post the wiring diagram. All you will need is a 1-microfarad capacitor and a 1-megaohm resistor (1/4 or 1/2 watt) from Radio Shack.

Here we go...
O2%20Sensor%20Wiring.jpg



The color codes on our sensors may be different and I haven't taken a look yet. I would compare to a wiring diagram to our cars to make sure. This is for representation only. The black wires are the heater wires. The blue wire is the sensor signal wire. The white wire is the sensor ground wire. Do not make this modification to the first O2 sensor. You WILL have problems if you do. This basically keeps the sensor voltage on the second above .5 VDC making the computer think the catalytic converter is still there and functioning. I've done this on a few Mitsubishi and Ford vehicles and workes beautifully. My personal plan is to drop the primary and secondary cats, put on a header, single high flow cat, good exhaust, mod the O2 sensor and enjoy the ride.

[ 12-05-2001: Message edited by: rodslinger ]
 
Thanks rodslinger.That is some good info. I gave you some stars for that one. I can't wait to put a header on this car. I think a header will release the most power out of any mod, besides N2O or forced induction. This was also discussed on the racing beat site saying that the 1st cat was robbing the engine of the most power. If people put the cams, CAI, and other mods, then later put on a header, they are going to be shocked at how much power the two cats were holding back. Just my theory.
 
Too bad we have smog checks and visuals. I will do it cause I can, but it kinda sucks for those who need the CARB exemption.

Thanks for the diagram, now I just need to ensure which header to use. If the BOSAL header from the 2.0 probe will work, I will hook all of you guys up phat.

Please someone tell me if it's a for sure thing. I guess I could just buy it and try it, if it doesn't work, the exhaust will be for sale at probetalk.com. hehe. I'd rather leave the guesswork out of it and hook everyone up.

Thanks, Rishie
 
As for emmisions checks, I think one cat will do. The people doing the check don't know that your car originally had two. Most cars only have one anyway. Correct me if I'm wrong though.
 
Originally posted by frady2001:
<STRONG>question, doese removing the first cat. void our warranty or hurt gas mileage.</STRONG>


YES, If you modify any part of the exaust before the second cat, then you will void your warranty.
Not for sure about gas mileage, but IMO I doubt it.

[ 12-07-2001: Message edited by: MP3-Owner ]
 
YES, If you modify any part of the exaust before the second cat, then you will void your warranty.
Follow up Questions: Why is that? Doesn't it depend on you State emision laws? And doesn't a mod have to be at fault/cause damage to void warranty? What's your source?Just curious.
 
Adding the header won't necessarily void your warranty. They have to show that the modification done is directly related to the failure of the component. It would be reasonable not to cover a burnt piston or blown headgasket when the car rolls in with a custom turbo kit mounted to it. But they can't deny a leaking valve cover gasket for replacement of a header. They aren't related. Secondly, removing the cats and adding a header will only change the sensor values to the second O2 sensor (which is what the mod fixes). That second sensor has no impact on the cars performance anyway. It is only there to make sure the cat is working. They may try to deny a claim but would have a doubt they can give a legitimate or factual reason why.
 
the only thing you really have to worry about when removing the cat is its against Federal law to remove or change the cat before a certain amount of milage (50,000 ive been told)

are you guys sure we have two cats. this is from mazdas web site

Emission Control: Single 3-way catalytic converter

i know on my ZX2 i had a single cat and a resinator. i took out both of them.
 
@Freek;
Hey man, I'm "sure" that we have two cats, one right off the header, and the other after the resonator. I installed a complete Bosal exhaust system this weekend, and once your under the car, you can see the 1st cat. But your right... Mazda site list 1 3-way cat on the specs sheet. Who knows?
 
I have two cats on my car and a resonator. The first cat is in the header bend(If you remove the shiny metal shield you will see it) and the second cat is after the header, just in "front" of the resonator.

As for my source on the removal of the cat?
I heard that from a local exuast shop, when I went in to have them redo my system.
It is true that the dealer cant turn you away just because you have mods to your car, they DO have to prove that the particular mod you have caused the problem at hand.
 
If you take off the "precat" or the first cat, or whatever, will we pass emissions? Or do we have to hook it back up to do so?

Also, can this mod co-exsist with a turbo?
 
as for emissions. it really depends on where you live. i could do it in MO. cause they only have a visial check. as for a state like Cali it would be hard, but it can be done. just add an aftermarket cat after the header.

Coolhand - thanx i wasnt sure. plus i dont have my car right now to check its in the shop. i was just going off of what i remeber comparing it to my old car.
 
I live in NJ...They put some little wand near your exhaust to test it. How much would a new cat run? How much would it hurt HP? Could I easily take it on/off?
 
i know that the 95-97 probe with the 2.0 has a pre-cat. if you can find a header that works on that car it should have the correct o2 sensor input to stop the check engine light from coming on.
 
Here's my idea about the cat. When a less expensive header comes to market( not the ungodly $739 one from Corksport) we can also buy the exhaust system from Racing Beat or Bosal. I've read they have two different exhaust bolt on's. One is for Cali, and the other is called a Federal exhaust system. They only difference is that the Federal one removes the second cat under the car. The Cali one doesn't. In place of the one under the car in the Federal sys. is a straight pipe you can bolt on and unbolt very easily. During the emissions tests, you can just take off the pipe and put back in the cat. I've heard that you can put in the exhaust in less then 2 hours, so the one pipe must be less than 30 min to do. Just an idea.
 
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