Hello,
I have a R53 2006 Cooper S. My front pipe broke under the shielded flex section. I want to replace it with something economical. If I put the cheapy ones on ebay on wiht the "test pipe" will that make my check engine light go on?

Any recomendations for a replacement?

Thanks,

 

I have used the Flashpoint Mk1 from Way Motor Works
Replacing the Manifold

Tips to Replace the Manifold

Sound

 

yes it will set a p0420 code and you wont pass emissions. if you want to be economical you could have someone weld the existing cat you have onto the new header your planning on getting for cheap and be legal that way.

 

Getting a code and passing emissions are a different thing. The code can be avoided both electronically and mechanically. Emissions is another story; if your state actually tests tailpipe emissions, you'll be out of luck.

If you go catless, use this Vibrant O2 simulator: http://www.summitracing.com/parts/vp...FUkS7Aod21wAtg

 

@thebigchill what does the O2 vibrant simulator do and where do you install it?

 

It's a mechanical fix to fool the ECU into thinking that there's still a second catalytic convertor, should you choose to eliminate it. You have it welded into your aftermarket exhaust system, downstream of the header. The second O2 sensor is installed into it.

Supposedly the R53 is very picky about this, and this is the reason I use and recommend the one I linked to; it has 3 different inserts that alter how much exhaust gas reaches the sensor. This is unique to that product.

 

The First O2 sensor before catalytic is used by the ECU in close loop to it will used by ECU how much fuel to put into the injector. It generates a wave signal in between 0.1V and 0.9V (indicating lean and rich), so the ECU will control the fuel them.

The second one after catalytic will be used for Emission control to determine how O2 is present, suppose the catalytic should absorve CO2. If you look the wave signal in the O2 sensor the first one should be oscilating and the frequency is variable of RPM and the second one should 0.1V at idle and should remain at 0.9V at RPM higher than 2,000. So the O2 simulator is used for replacement of the second O2 (after catalytic to simulate that wave).

Here is one example in a normal R53




More technical specific information about the operation of the O2 sensor can be found using this document. look at pages 26, 27

http://www.bmw-planet.com/lib/mini/E...20OVERVIEW.pdf

 

How far down stream would you recommend putting the second O2 sensor to ensure the check engine light would not be coming on? And also wouldn't the better idea be to limit the amount the exhaust gas reaching the sensor so the smallest insert would be best?

 

Put it as close as possible to where the original bung and sensor location existed.

Yes, the smallest insert worked for me. 8 months catless, and never a CEL.