I read in another post previously about being able to tell if your car is running rich or lean while driving by having the 6 and 12 pins connected while driving.

I'm wondering if this is correct. And I would like to know if I'm supposed to jumper the two pins before starting the car or after the car is already started.

Thanks in advance.

 

Partially right...connect the A and B terminals just like you were going to check for Check Engine codes... A and B are the two furthest to the right terminals on the top row.

Connect the two with the car off and then start it. Don't connect them while the car is started. If I remember correctly, Even between Check Engine light on and Check Engine light off means you're running normal. If the light stays on more than it stays off, then it's rich...and if it's less light and more of no light, then lean. I THINK!