which high flow aftermarketis best too put behind the OBX header.

take into account that the cat has too have an O2 sensor....has to be affordable and performant

i do not want to cut up my OEM header thats why.

cheers

 

Cut up the OEM cat... here's why:
1. Why do you want to keep the OEM header intact? Unless you plan to reinstall it when selling the car in the next 12 months, I bet you'll never use it and one day find it in the shed out the back..
2. Cheap aftermarket cats like Magnaflows ($65) are just that--cheap and may not last very long.
3. Expensive and good cats like the Random Technologies ($170) do not come with an o2 sensor bung.
You will have to get any of the above cats welded to flanges to fit your header anyway, so you could get the bung welded to the RT cat at the same time (the Magnaflow comes with a bung in the right place even.)
And you *know* that the stock cat won't throw a SES light...
good luck,

 

i want to keep my OEM because they will fail me when my car is checked yearly by local TUV (place where they check the tires, emissions, suspension, etc....) with all these aftermarket "illegal" parts fitted . In belgium the only thing that is legal is a rear muffler....

so i would rather not like to take the risk of being caught with a cut up OEM cat welded to an aftermarket header, because the OEM header and cat would cost me 1300 euro for replacing it again and passing the TUV.

 

I am not quite sure why you need to replace the OEM cat. I think it was WebbMotorsports has shown that the stock cat can flow enough gas to support a 250 - 300hp engine.

Maybe you could find an OEM cat on ebay and weld that on to you new header, while still maintaining your original header.

 

yes thanx Bilbo,

i was thinking about that option too, i posted on dutch and belgian minisites that i was looking for an OEM cat, but without succes... headers are a NONO in belgium, there a gogo in Holland.... but still i can not find any OEM .... there is an autoshop selling a OEM header with cat attached, but hes asking 250 euro.... so for that price id rather buy a more expensive setup for my header....

I tried ebay too, but i can not find any OEM cats ?

If somebody has one and does not need it anymore, please sent me an email or pm, we can discuss price and transport too my country ?

 

You might want to try the NAM marketplace and post a WTB:OEM Cat (WTB=Want to buy). I believe the forum is called "All other MINI parts and items for sale" or something close to that...

EDIT: You did that exactly as I was typing ...

 

i am faster then your own shadow........

thanx for the advice

 

I just had a high flow cat put on today. I used a Random Technology 2.5" cat. I'm very pleased that I added it. Using no cat was just too obnoxious and you could smell the burning gas constantly. It did not necessarily make my car quieter...it just turned the exhaust tone into a much more pleasant sound. It doesn't have an o2 bung, but I'm sure you could add one.

I don't see why you would use the OEM cat though. To me it doesn't make sense, but oh well.

 

Dumb question, but if they're going to fail you for having a header regardless of the cat why put any cat on it at all? Sounds like you're going to have to put the OEM header/cat back on once a year either way. Just get an 02 simulator (I believe they're cheaper than a cat) so the CEL doesn't come on and go motoring!

 

thanx, but cant i leave the EML light on and just drive around for a year, and when time comes to swap the OEM back under it , i think the light will go back off right ?????? i hope the light goes back off ......

I am worried about noiselevels on my car when using just a testpipe, what i heard on diff. threads was that without a CAT the noise is going to be very loud inside the cabine ?? Plus i do not have a resonator anymore too quiet it down a little....

 

How can i make the o2 bung in the cat, and maybe i do not need to make it anyway... Can't i stack the o2 sensor somewhere underneath the car, just to reuse it when the OEM is fitted back on once a year ?

 

miniracer1: the problem with a SES light on all the time due to the o2 sensor is that you'll never know if any other condition has occured to trigger the light--it can't go on twice!
Yes, you can simply mount the o2 sensor on the frame of the car near the exhaust. Even with an o2 simulator you need the sensor since the OBD checks for the heater on the sensor (12v) and if you remove the sensor, the absence of the heater will trigger a code. I suppose you could figure out how to simulate the heater circuit too.
cheers,

 

yes, lets work out how to tell the heater its working. Im pretty sure some resistors would work. I am about to do the same for my car

 

JEEZUS ............ what a lot of hassle to trick the system.... ill better forget about the new cat.... ill just buy a more expensive system, without having to think o2 sensor bung,

or....hmmm... maybe i could just take the plunge and do not worry about the noise and put in the testpipe... araaarrghh.... :impatient what to do what to do ......

pfftt..... a lot of research to do before one can make up his mind.... everytime i think i come up with a solution some other issue comes up to be solved.....

Gandini, thanx once again for the answer, u helped me out before and i appreciate it.....

 

How much was the cat and from where did you source it? Oh, and are you throwing codes? I know, you've only had it on for a day, but please update your impressions as time goes on.

 

The cat was $157 and I got it from this link:

http://dezod.com/pd_random_technolog...nverter225.cfm

Fit's perfectly, had someone weld it in within like 10 minutes.

Nope, I'm not throwing codes...I have an o2 simulator. I've been using it since I installed the header which was about 3 weeks ago...never have had any codes.

 

The Cooper and the MCS use the same cat. Between the salvage yards, ebay, craigslist, they are out there! I'm keeping my stock header and cat so that when my current stock cat fails, I'll have another to swap...

 

This would be interesting just after the cat huh?

http://dezod.com/pd_apexi_exhaust.cfm