Looking for some feedback on this.

I have a 2008 Clubman S and just got my exhaust system installed. I installed an Exhaust Depot high flow catted down pipe and a custom exhaust. The custom exhaust is resonator delete, hollowed out 2nd cat, and straight pipes back (no mufflers). Naturally this sound vicious, but I am having some issues.

A friend of mine has the same custom exhaust on his clubbie but no down pipe.

The difference is mine is louder and drones at highway speeds while his doesn't. Mine also smells on startup and is dumping a lot of fuel in the DP it seems, because the smell coming off the car is noxious. After some time the smell goes away, but it is annoying when starting from cold. Back pressure issue? Exhaust pooling in the hollowed 2nd cat causing the smell?

Even though the ED down pipe is supposedly CEL free, I have thrown a few CEL on occasion at random times. The error is the cat is running out of range.

Like I said my friend runs the same exhaust on his without the down pipe and gets no drone and no smell and it sounds great. Those are the issues I am really trying to fix. The sound is great, well tbh a little too loud. After talking to a bunch of different people, I have gotten suggestions to add a resonator back into the system which will help with the drone. Other have said to add a second high flow cat which would alleviate the smell and the drone. Then my other option to replace the DP back to stock.

I would love some more feedback and reasons why to go one route or the other.

Z

 

Sounds like you're destined to go back to the stock exhaust.

 

I have the Akrapovic exhaust and have nothing of the sorts. It's catted and if you really stick your head back there you get a smell but passengers have never noticed. No drone either. Yes, CEL but i cleared it with a tune.

 

Check for leaks. If you are getting a leak pre 02 Sensor if will throw a code and cause you to run rich. Did you change the DP gasket when it was installed? Did you torque the nuts down properly?

 

Any aftermarket DP will throw a code. Even the high flow catted ones and the 100-200 cell cats, From what Ive read. Best thing is to get a tune first and see how it goes after that.

 

We checked for leaks after all was installed. Checked the welds and connections. Put a brand new gasket on when installing the DP. It's weird. The trowing of codes seems completely random. It has only thrown a CEL twice since installed. Just drove 12 hours from Denver to Vegas with no codes at all. The exhaust smell is only on startup. When we would stop to get gas, eat, etc no smell.

I am wondering if I wanted to keep the DP, would putting a 2nd high-flow cat inline (where my orignal cat used to be) would help ease the fumes? Or maybe, since the 2nd cat is hollowed out and the resonator is gone, there isn't enough back-pressure in the system and the exhaust pools in the hollowed out 2nd cat before it gets forced out. Maybe adding a resonator will help with the back-pressure? Seems like I am basically going back to stock in that case minus the mufflers...

The idea with how the exhaust works on the clubbie, is that there is more area for it to travel vs the R56 due to the length of the car and split in the rear, which allows a straight-pipe design to create the throaty yet mellowed tones without the need for mufflers. My friend has it on his clubbie minus the DP and sounds great. I am trying to see if I can modify the exhaust to allow the DP to exist. Naturally the DP will add more noise into the system, but taming that added noise to the current exhaust without adding mufflers is what I am trying to see is possible.

Of course this is all hypothetical until I can test all this on the lift.