I just turned over 100K on my '04 MC and have been noticing a drop in fuel mileage over the past several months. Nothing drastic, but 4-6 mpg difference. I have replaced the spark plugs (NGKs) and air filter (Hengst) in the last little bit and am thinking about replacing the O2 sensors.

My question is, what are opinions of universal o2 sensors, and do I need the 4 wire sensor for both of the sensors? I have used universal sensors on all my previous vehicles, but was unsure how it would affect the MINI.

Thanks for your help!

 

as long as it's a universal for your style o2 your fine with it.

 

I found them on partstrain.com for the 02-07 MC for $32.11 each. Pretty good deal if they are good. Are they both 4 wire?