22mm crowfoot socket wrench (had to buy a whole set to get that one - for O2 sensor - fits much better than the slightly oversized 7/8" O2 sensor tools that I could find). I have a couple 1/4" drive 10 mm sockets (one regular and one swivel), and a regular 10 mm crescent wrench, brake bleeder style wrench, and ratcheting box-end wrench, and I needed just about all of them to get the damn 10 mm headed bolts off and on from the turbo upper heat shield the other week. I was too lazy to take the front end off into service mode and I have big hands and there’s just enough room to do it.