Recently, our beloved ’96 Saturn SL1 failed to pass emissions inspection. It turns out that we had two bad sensors, an O2 sensor and the engine coolant temperature sensor. As you can see in the picture, the temperature sensor was in pretty bad shape. Both were easy to replace, it took maybe 30 minutes total. The main problem with the bad temperature sensor was that the car’s computer thought the engine temperature was -15 degrees, even when it was 50 degrees outside.
As of late, the engine had started to run more rough and kind of choking on itself. I thought it was just due to the car getting old. Little did I know that it was just a $15 part I needed to replace.
I replaced the sensors and went through a few driving cycles and our little Saturn was able to pass emissions. It runs a lot better now too. With my last tank of gas, I got an extra 7 miles to the gallon (now 37 mpg.) I’m kinda excited that it is only about 2,000 miles short of the 200,000 mile mark.