Just replaced the sensor - pretty easy job but wtf is up with the plug location ...its tucked on top of the sub frame and access is almost impossible. A fiddly one-handed job but yes...possible!
Just changed my pre-cat O2 sensor AGAIN to try and diagnose a NEW misfire (the fun never stops...!) I remembered this method of accessing the plug and indeed you can access it from the passenger wheel well. You can even fit two arms in there to hold onto both sides of the plug. Thanks barker22 this is easily the best method, entire job took 5 minutes!I know it's a late reply but just wanted to add my take on this as I did mine today
I found that if you take the front passenger side wheel off you can get both hands in, you kind of have to hug the disc brake a bit, but I gave up trying to get it from below. Hopefully this may help someone searching