I recently bought a 1991 Honda Acty. Got it home and all seemed well but after driving it around I noticed that the temperature gage wasn't going up. I looked under the truck at the sensor to find that the sensor was cut and the wire grounded! Looking around it seemed that the correct sensor was $100+ from Japan with no one this side of the world selling it. I decided to try a generic one before shelling out the big bucks. I found this one https://www.amazon.com/gp/product/B009HW44F4/ref=oh_aui_detailpage_o05_s01?ie=UTF8&psc=1 for about $17 with prime shipping. The threads for the new ones didn't thread into the exhaust so I put the old nut back in and put the sensor through and pinned it against the brake line. It's not the best and leaks out a bit but it works and it's a heck of a lot cheaper than buying the actual sensor. I've looked through the service manual but I can't figure out if the sensor is just for the temp gauge or if it controls anything. Does anyone know?