One of the issues I'm dealing with on my R53 is the "P0420 - Catalytic Converter efficiency below threshold" code. I know it's due to running catless currently, but I am looking into aftermarket cats to resolve the issue. I am really interested in the G-Sport GESI high-flow cats. They have one model that I have read is about 90% efficient and another much more expensive model that I have read to be 99% efficient. All I care is that the code is cleared and stays off, but I don't want to spend more than I have too... does anybody know what the efficiency threshold is for the first gen MINI's?

 

Get inpa an reset you fuel adaptations. Had the same problem. Cleared my code. Been 4 months with no issues.

 

Excuse my ignorance... but I'm a little unclear what you are talking about here. A quick Google search told me it's a diagnostic tool, but I'm not sure which one I should be looking at.