Dumping raw fuel into the cat can't do any good.
Thankfully the guys with the slide rulers agree, and have the ECU ignite the fuel with the exhaust stroke spark... ?
It's how most of the modern cars (our Rs included as I understand it) pretend to after fire. Spit a bit of fuel into the cylinder during the exhaust stroke and spark it off with the valves open to get the POP to transmit out the tail pipe.
My '12 Cooper S did the "burble and pop" when in Sport mode, and was silent otherwise - this was stock from the factory. (You should see the threads on NAM about the burble and pop - both loved and despised!) ?
I gather that as long as the fuel has been detonated prior the cat, no harm done, and that the amount of fuel is really negligible... I was never able to detect an economy difference with my Cooper in Sport or Normal mode - and I watched it closely. Any traffic or heavy footedness seemed to obscure the difference.
I could have done without the burble and pop myself, sadly though, other changes like heavyer steering and a lighter throttle feel came with the Sport mode as well.
In the OPs case, I'd take the power and dump the pop... But that's just my opinion! ?
Eric
