does anyone think there is a way to gut the cat converter and retro fit the o2 sensors ? so that the car will pass visual and emissions inspecs. my friend told me he did it on a friends mazda and it made a noticeable difference.i'm thinkin that if it is possible it would be worth it. i just don't wan't any problems down the road.

 

Anything is possible... If you're in a place where you only get the OBDII scan and not the "banana-up-the-tailpipe" routine, you may pass. Some MINIs seem to not trip a CEL sans cat, while others seem more sensitive.

Split the cat on top and gut it, weld it back up... To avoid tripping a light, you could try the O2 Simulator on the post-cat sensor...

Some feel that running sans cat may cause the car to go into open loop ECU mode, too. Closed loop is better, but who knows?

 

Your problems down the road will come when you have to take your MINI in for annual emissions testing. If it doesn't pass or if they notice that the cat has been opened and re-welded, you'll have to fix it.

I wouldn't monkey around with it unless you have done every other power increasing mod and still want more.

 

Several of our surrounding counties have sniffer tests, but if you have an OBDII car in my county there's no sniffer test... Therefore, if the computer thinks everything's okay, it's okay. They don't even examine the exhaust system...

 

Isn't the whole point of the second O2 sensor to 'tell' the car that the cat is working properly? If it never senses a change, one would think that would trigger an error code.

A request - give your post a title vs. a generic 'please reply'. That way people knowledgeable are more likely to go there and assist.

 

I agree with much of the above, but just an FYI, if the EPA ever finds out they'll slap you with a $1500 fine. Sounds loke the buddy who did this on the Mazda would have a better understanding. Also do a search for pre-cat, someone cleaned that up and noticed a huge differance and then possibly switched to a high flow cat, they seemed quite happy.

 

thanks for the good advice guys. i'm definitely thinkin about givin this a try. hopefully everything will work out.i don't plan on ever selling the car so.

 

It will work ... whoever mentioned about the rear o2 only telling the computer it's working is correct. The rear o2 doesn't oscillate like the front one does though, therefore, the less movement the better. Don't ask me the hows and why's, but that's my understanding as an ls1 tuner.

 

Nope. $25K fine. See http://64.233.167.104/search?q=cache...+federal&hl=en

You really dont want to do that or, I hope you got some free money to pay that fine if caught.

 

Philadelphia has bad air quality and you want to totally disable your car's primary air pollution control components...

 

you ever hear of septa buses that drive around all day with one passenger in them. i 'd be more concerned about that. not to mention the other 50,000 people in this state that have allready done this mod to there car.not saying i don't care about the environment . i don't litter or anything like that. i'm just saying read my screen name. sorry if i offended you with my ignorance . to everybody else, thanks for the solid input!

 

It's the pre cat not the main cat. It would be like buying an aftermarket header with a cat.

My header Broke at the pre cat weld and the pre cat was damaged. I had to put the car back together that day, so I pulled out the element and welded it back together. I wish I would have remembered the extended emissions waranty and got a new one from mini. Somehow I think they would have denied that claim too. Anyway, it did give a little midrange power and a sportier tone.

Something else to consider, if you have a cat back, is to fabricate a larger replacement piece for pipe after the main cat and before the cat back. I did this this weekend and made noticeable midrange and top end power. It sounds good too. It's louder when I get on it, but less drone in the cabin while at part throttle. Not sure how well it will work with the pre cat in, but worth a try. You do have to weld in a flange and o2 bung.

Next I want replace the pipe from the main cat to the flex joint to get rid of the open chamber that pre cat leaves behind. It would basically be a header with stock primaries.

Also, the cel light will not come on with the pre cat missing. I don't know for sure how it will affect emmissions. I have heard that it is for cold climates. I figure I will have to buy a new stock header after blowing the chance for a warantied piece. Now I am just seeing what is possible with the stock part. It has worked well for me.

Edit: oops, mine is a mcs.

 

I agree. And I'll give you the standard NAM response to the "more power" question in regards to MC's: Why don't you just get an MCS?!?!?!
But even if you want to, try and consider going with a high flow cat or SOMETHING instead of no cat or a gutted one.

Remember, they are on our cars for a reason, and it's not to keep them from going fast. So don't be foolish.

 

this should help me . new header , gutted cat , and these should do the trick

http://www.minituner.com/products/?s...&productID=477