More cleaning tips…

1 Breaking in

You’ll have to get past a grille to access the wires. It’s is often held in by a sprung clip. Look for a recess to get a small screwdriver underneath. Beware of the clip flying out.

2 Tired wires

If the wires are sagging, they may be on their way out. This sensor in this photo became increasingly erratic before replacement, presumably as the wire stretched. It eventually broke completely.

3 Dodgy connections

Erratic engine performance may be due to a poor external connection or a dry solder joint inside the unit. Older models can be opened up. Melt each solder joint and let the solder re-set.