I assume you have p0420. If your catalytic converter and oxygen sensors are original, they all should be replaced to have an efficient emissions system.

Answered by F4I_guy (expert)
3,238 answers provided

F4I_guy is correct. However, keep in mind that even though the code indicates a bad converter, often times this code is caused by a bad O2 sensor. If you have a scanner, watch the output from the downstream O2 sensor. It should vary between .35V and .55V. If it goes beyond that in either direction, the O2 sensor is the issue.

Answered by Jacobandnickolas (expert)
57,318 answers provided

Thank you so much all...
If I repair then what is repair cost ? may I ask ?

Thank you again.

Response from tommycho5740@gmail.com
1 question asked

An O2 sensor is around 75 dollars plus labor (if that is the problem) An aftermarket converter shouldn't be much more than 150.00 + labor. Because there are a few O2 sensors, and the cost of the converter, that is why I recommend checking the sensors so you can save the money on a converter if it isn't bad.

Answered by Jacobandnickolas (expert)
57,318 answers provided

understood and I will make sure of it.
Thank you so much all the help to all.

Response from tommycho5740@gmail.com
1 question asked

Glad to help.

Answered by Jacobandnickolas (expert)
57,318 answers provided