Visit me at: http://www.ericthecarguy.com/ O2 Sensor Video: https://www.youtube.com/watch?v=NIzcztO-CCs Discussion about this video: http://www.ericthecarguy.com/forum/18-The-EricTheCarGuy-Video-Forum/42514-p0420-how-to-diagnose-a-bad-converter#42610 I know this video will not only save people some money but also I think it will solve a lot of confusion concerning the operation of the catalytic converter. These tests work as you can see in the video. So the next time you have a P0420 or someone tells you your catalytic converter is bad you'll know what to do to find out if that is indeed the case. Stay dirty ETCG Due to factors beyond the control of EricTheCarGuy, it cannot guarantee against unauthorized modifications of this information, or improper use of this information.  EricTheCarGuy assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. EricTheCarGuy recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video.  Due to factors beyond the control of EricTheCarGuy, no information contained in this video shall create any express or implied warranty or guarantee of any particular result.  Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not EricTheCarGuy.