P0420 to P0430

My 2005 Tacoma V6, changed from P0420 to P0430 after 3 Cataclean used. Can anybody help me with this. Check Engine light on.

 

420 is for Passenger side.
And 430 is for the Drivers side.

So, you fixed one side, and now the other “broke”?

 

This is not supposed to happen. What can I do now?

 

Fix it

 

Confirm you have no exhaust leaks.
Confirm you have good 02 Sensors. (Use a scan tool)
Replace the converter(s).

I know that’s not what you want to hear.
But your truck is 18 years old. The converter(s) are probably on their way out.
Anything other than replacing the converter is temporary.

 

Start replacing cracked and dry rotted vacuum lines

 

For those wondering, 420/430 is a Catalyst below efficiency
If those are the only codes, it’s not likely to be anything other than an exhaust leak after the A/F or a bad converter. If those codes are accompanied y other codes, then there is a chance those codes are secondary. But it’s not looking good for OP.

 

Go to You Tube and search the problem. I’m on step 5 of around a dozen or so fixes and it’s been 2 days without the engine light coming back on.
What I’ve done so far.
1. Clean and retighten negative battery terminal.
2. Pour bottle of Cataclean in gas tank.
3. Replace spark plugs.
4. Check for vacuum & exhaust leaks.
5. And lastly I added spark plug non-foulers to space out the downstream O2 sensors which seems to be working so far because every other fix made the engine light come back on within a day.
Get yourself an OBD II scanner (around $35) so you can clear the codes after every attempt.

edit: I saw another video this morning on my YT feed. You can try removing the O2 sensors and soaking them in toilet bowl cleaner for about 5 minutes (the toxic blue sh*t that looks kind of like Windex) which is supposed to remove the carbon build up.