Can't get it out - no leverage!
I also need to change the front Air Flow sensor on our 2003 Forester with the 2.5 NA. So I looked at the pics and great explanation by Peaty, and also got the crow's foot socket. But when I crawled under there and got the socket on the sensor, there was literally no room for the breaker bar to move to loosen it. One of the heat shield's "ears" that stick out for the bolt to go through is directly in the path of the socket movement (I will try to take some pics and post them). I tried every way I could fit my hands up in there, even tried the flair wrench that was suggested, but I cannot get it on the sensor at any angle that allows any movement.
I am at a loss for what to do next. Any suggestions will be greatly appreciated.
2003 Forester X 2.5 NA, 5-spd MT
Metro ATL, GA