universal O2 sensor - the purple wire "answer"
I bought the cheaper O2 sensor where you have to cut/connect the wires - also known as a universal sensor. The problem is the AVEO wires are white, black, grey, and purple and the new sensors come with white, white, black and gray. There are a bunch of conversion table out there and one that came with my new part - but none said what to do with the purple wire. Anyway, someone on the web said the AVEO purple goes on one of the white wires ( doesn't matter which one) and that turned out to be correct. So black to black, white to white, gray to gray, and the final white wire on the new sensor goes to the purple wire on the Aveo harness/plug. The check engine light will stay on after the fix, until you unhook the neg battery terminal for a few minutes and then reattach and start her up - light stayed off. I replaced the lower sensor (given the code readout) which is passenger side near the bottom of the oil pan and just before the fabric looking flexible exhaust coupling. There is a protective shelf below the sensor to it doesn't get knocked/broken with road debris. I was able to get the sensor unscrewed with vicegrips. The thing failed after 30,000 miles on a 2009 car. There were no symptoms other than the engine light but I wasn't monitoring the gas mileage.
