I was having trouble with the two passenger sensors because the aluminum under the paint was corroding. When I would put the car in reverse, the sensors would cause a solid beep as though I was right up on something. I looked into replacements only to find that they would cost me 200 bucks a piece! I removed the sensors, used a razor blade to remove the bad paint, and cleaned them up with a non-abrasive wheel. I re-painted them with dupli-color paint. The paint I used did make them a little less sensitive, but they work almost completely as intended. I hope this posting will help anyone having the same problem who doesn't want to empty thier pocket book with replacements!

 

How did you identify that it was the right two?

 

The paint on the surface was pitting from the corrosion underneath. I have northern weather/salt to thank for that!