Well, chalk this up to "things that only happen to me" but I'm sure this has happened to someone. When removing the tube between the 2ndary air valve, and the exhaust manifold to access the spark plugs on the drivers side (2016 SR5, 106K, figured it was close, and it was a BEAUTIFUL day, so I'd do them) I broke off one of the studs at the exhaust manifold end. Yes, I had hit everything liberally with Kroil, and this was the ONLY fastener that gave me any trouble. In fact, it didn't really fight me at all, it just BROKE. I was using a small 1/4 drive ratchet, and snapped it off REALLY easily. I put a clamp in place temporarily as I try to figure out how to remove the broken piece. Its really cramped, and getting in there with any type of drill will be tough. Anyone ever had to do this?
Have not had that specific issue happen to me, but the driver's side is always a PITA. I've had the internal flap or vane on the air valve break. Twice I've had wires come loose or out of the back of the harness plugs over there requiring replacement or repair. I dread that side, but somewhere here is a video of an 11-year old girl who does the job easily.
Right angle drill, or right angle drill attachment should get in there. Small drill bits, like Saker mentioned, are threaded on one end and screw into the head of a right angle drill attachment. They take up much less room than a chuck. I've found heat seems to work better than Kroil like products; but can't hurt to use both. Heat only if you can do it safely and not fry nearby parts!
If you have trouble finding right angle drills and bits, look into aircraft supply companies that cater to the homebuilding crowd. Aircraft Spruce and Wicks aircraft supply are two.
Have not had that specific issue happen to me, but the driver's side is always a PITA. I've had the internal flap or vane on the air valve break. Twice I've had wires come loose or out of the back of the harness plugs over there requiring replacement or repair. I dread that side, but somewhere here is a video of an 11-year old girl who does the job easily.
It is indeed a pain! I think the 11 year old does the plugs on a pre-air-injection model. Nothing to move!