Review on 🔍 ECCPP O2 Oxygen Sensor 234-4375 for Ford Focus 2.3L (2003-2007) by Joshua Cameron

The "Check Engine" light came on and the car started stalling at idle. I took the car (Ford Focus) to O'Reileys (however it was spelled) and they confirmed with an OBDII scanner that it was an oxygen sensor (upstream) - I should have an OBD2 reader by now, but they are free. Everyone, I sincerely think this block would fit downstream as well. I don't understand why Ford makes two different spark plugs. The oxygen sensor worked well and was cheap and quick to fix (5 minutes or less) but you need a special tool (mine, bought off Amazon for $8, is a slotted oxygen sensor puller). Within 30-40 miles there was a problem: the car went to lean on the first embankment, this eliminated it. I think an oxygen sensor would also work downstream. Changed because the car started to stall while idling.