Code P0420 help

[mgcorreia]

Hey, I just bought a 1997 4runner 4cyl with 200k miles. It drives good but once in the while it throws me code P0420 while cruising on the freeway. What do you guys think? New catalytic converter or oxygen sensors to fix it? Or both? I have to get a smog cert before I can register it, do you think it will have problems passing with this code? Im in san diego, which has pretty strict emission standards.thanks!

 

[hambob]

its either a leak in your exhaust before rear 02 sensor, the rear sensor itself or a bad cat. I dont know about cali emmision. Good luck

 

[mgcorreia]

thanks, is there a "diy" way to check for an exhaust leak?

 

[chadsy]

thanks, is there a "diy" way to check for an exhaust leak?

Here is a helpful video for your situation:

How to Find Exhaust Leaks - EricTheCarGuy - YouTube