[jlex]

No need to remove engine tin.
put the rear wheels up on jackstands, then remove the left rear wheel.
Just follow the wires that come thru the wheel well that lead over to the flywheel.... you can't miss them. Two of those wires lead to the speed and reference sensors. The third wire leads to the cylinder head temp sensor. You can't miss them...
From your photo, the two wires that lead to the sensors appear with the cht sensor wire. The two that have the insulation crumbling off of them and are showing silver underneath are the ones that will be replaced with the new sensors. From the looks of those wires, that's probably your problem.