Review on Enhanced Denso 234-9120 Air-Fuel Ratio Oxygen Sensor by Jim Kriegshauser

My 2005 Subaru WRX STi started out idling and with fluctuating throttle response while driving. According to the Denso website this is the correct part for this engine which is the same as dealer part #22641AA211 (which is of course more expensive) and rightly so. It's 30 inches long, which is exactly what's required and proved to be an exact replacement for the existing sensor. I haven't seen any evidence that this is fake. Replaced part, now everything is perfect. Maybe it will improve my fuel economy a bit but I have to say I'm not holding my breath!