P0420 code?

[tekfire07]

Hi, i got a P0420 code. Reading other post. It mentions exhaust leaks could be a cause. I have a hole on the joint of the extension tail piece and the muffler. It is the size of a silver dollar. Can this be the issue? Or is it to far down stream of the O2 sensors to be a issue?
Thanks in advance for your time and any help.
Erik

 

[B-train]

An exhaust leak post O2 sensors will not cause any issues. You have further to dig/test.

 

[B-train]

Do you have access to a scanner that will show you what the O2 Sensors are reading? The code is for low catalytic efficiency. A failed post cat O2 can be a culprit. A damaged cat from years of oil burning can be as well. Hopefully it's just a sensor and you're on your way again

 

[tekfire07]

Thanks for the information. My new scanner will be here tomorrow. I will investigate further.

 

[Fless]

You can swap the downstream O2 sensors to see if the code moves to the other side.

 

[BG1988]

Hi, i got a P0420 code. Reading other post. It mentions exhaust leaks could be a cause. I have a hole on the joint of the extension tail piece and the muffler. It is the size of a silver dollar. Can this be the issue? Or is it to far down stream of the O2 sensors to be a issue?
Thanks in advance for your time and any help.
Erik

the best way to test it in generate some diesel smoke into the intake this will trigger p0420 right away if the cat is bad