i did the same thing last month, put some silicone on a 5p coin and cover up the hole, then get on the phone with toyota and order a new bolt. and yes undoing the other 4 will release the rocker cover hope that helps you
hey mate i think they're M11's, im trying to buy some factory ones too for my front seat belts as the last owner had harness, any chance your selling yours lol
sounds like the ground wires that are usually near idle control valve(the ground is usually attached to one of the 2 bolts holding the idle valve in the mani) maybe last owner extend to back of mani??? - just a guess get a pic or trace the wire back and see what part of the loom it came of then compare to a friends starlet
im sure if your engine light came on you could do a diagnostic check through the engine bay port and find out if its a sensor issue, even if the light doesnt stay on it mite still tell you just search on here for the method on bridge the to pins in the diagnostic port