Step 1: Materials
1. A 05 Saturn VUE
2. O2 sensor AC Delco Part # 1255-8143 (I got mine from Ebay for $50 new)
3. O2 sensor socket. ($10 from Advanced Auto Parts)
4. 3/8 drive ratchet.
5. 10 min of your time.
(Note: In the picture I am showing the old O2 sensor that came out of the vehicle. I had already replaced it just prior to doing this instructable.)
Step 2: Locate the O2 sensor
Please make sure that the engine is cooled down. We don't want any burns due to this instructable.
Locate the faulty O2 sensor. I have marked on the picture where to look. It is located on the back side of the engine between the exhaust manifold and catalytic converter. ( I would also like to add: This is Bank 1 Sensor 1. If you had a computer scan that said O2 sensor Bank 1 Sensor 2 was bad then you will need to replace the O2 sensor just behind the catalytic converter. )