Review on 🌡️ Optimized Engine Management 9342 Coolant Temperature Sensor by Chris Meers

Bought this sensor as part of routine maintenance on a 1993 Accord I bought for my wife last year. I replaced this sensor because I had high mileage cars that would not start due to an ECT sensor failure. My wife's Accord has around 200,000 miles on it, as I replaced this sensor along with other tuning parts as a precaution right after buying the car, I didn't have much experience driving this particular car before replacing the sensor. Anyway, fast forward to about a year later. My wife hasn't had to drive much lately, so I regularly take her car with me on business trips. I was disappointed with the fuel economy the car showed. For some reason I could never get more than 22-23 mpg no matter how I drove. I started investigating this fuel economy issue. I found the torque converter was not locking up in 4th gear, but I had no DTCs for my transmission and no stored CEL codes. No matter how long I drove or how warm the engine was, the torque converter didn't lock up. After reading my service manual, I found that my car doesn't lock up the torque converter unless the ECU detects the car is up to operating temperature. I had already installed a new water pump and original Honda thermostat last summer along with all new coolant hoses and gauges so I knew the cooling system was working properly. I chose a Tama HS106 sensor (made in Japan) and compared its resistance values with the "OEM" values of this sensor. The Tama sensor showed approximately 25% less resistance than this sensor at 60F ambient. So the OEM sensor tells the ECU that the engine is colder than the Tama sensor. I replaced the OEM sensor with a Tama sensor. Immediately my torque converter started to lock up normally. I've been driving the car for two weeks now and have about 750 miles on it. My torque converter now always locks up at around 60 km/h. My fuel economy improved to around 25mpg under the same driving conditions as before (minus the drop in outside temperature). What annoys me is that this sensor wasn't effective enough to prevent the torque converter from locking up, but not enough to trigger the CEL code. If I hadn't known to check the torque converter, I probably never would have known that this sensor was bad. This faulty sensor cost me more fuel last year than I saved by choosing this sensor over a better one. Learn from my mistake. If you plan to use this sensor to repair your check engine light, take the hard step. I would recommend a Tama sensor, an original Honda sensor, or a BWD/Standard Motor Products sensor. But. not this one.