PO420 Code--Conveter?

[Ranger482]

i keep throwing a PO420 code, and it comes up bank one cat efficieny below limit. I initially thought oxygen sensor, but now i am unsure since i have had many opinions. Has anyone ever dealt with this before? Is there any way to test oxygen sensor?

Thanks

 

[dogfriend]

The P0420 code means that the Cat efficiency test failed. The test compares the O2 in the exhaust before and after the catalytic converter to determine if its still working.

More in this thread:

http://www.explorerforum.com/forums/showthread.php?t=154116&highlight=P0420

 

[raaizin]

You might want to try this. It worked for me.

http://www.brickauto.com/o2bypass/o2bypass.htm

 

[Ranger482]

Thanks for the link. When you install these, do you have to have a good oxygen sensors or can you use the bad one? Do these hurt your mileage at all or help it?

 

[1996xlt]

If you want to save $10 search around the ole net and you make your own with all the parts from your local Shadio Rack. My brother did it on his 98 GT made then for just over a dollar.

 

[raaizin]

Thanks for the link. When you install these, do you have to have a good oxygen sensors or can you use the bad one? Do these hurt your mileage at all or help it?

I still have my original O2 sensors at 181k miiles. From what I understand, this code is for the efficiency of the cat converter. If your car doesnt have any other issues it shouldnt affect gas mileage.