Front bumper parking sensors

[gurry]

I have a couple of questions about the sensors.

First off
The front bumper sensor has pushed into the bumper by a few mm. And one know a neat trick to pulll it back out without removing the bumper or undertray valance?

Second
Had a rear end shunt and replaced the bumper. All sensors are wired in but the park assist does not engage. Gives a long tone and then the led blinks to say its working butnon functional. Dropped into reverse and there are two sensors that hiss (working?) And two that do not.mshould I takeitthe non hissing ones are FUBAR and get replacements?



Many thanks


Garry