02 sensor 2006 Pontiac Grand Prix

I believe there are 2 of them both located on the exhaust system. If its the first one it is located high on the exhaust system between engine and firewall. Unbolt the front motor mount and roll the engine forward using a ratchet strap and you can fairly easily reach down to where it is. Takes a special socket to remove it though so unless you're well equipped with tools or want to buy tools, its probably a job best done at a mechanical or exhaust shop. The second one is further down and can be accessed from below the car.