Secondary catalytic converter question
 

Hello, my 01 base couldn’t pass smog because of a p0430 code. The shop diagnosed it and they said both the primary and secondary right cats were bad. They wanted 2700 for new cats and oxygen sensors which I thought was ridiculous because that’s half the price of the car. My question is do I need to buy a new secondary cat? I thought there weren’t any sensors past the primaries so it wouldn’t make sense to spend all that money. Any help is appreciated

You are correct - there is a sensor before and after the precat (on the header) but none that monitor the main cat (aka secondary cat). Id be curious how the figured that the cats are bad though...

Rumor has it that the most common cause of that code is a bad gas cap. You may wanna start there.

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Yea I'm not sure how they figured out it was the cats. If they just pulled the p0430 and concluded that it was the cats just from that I'd be pretty upset. I bought an installed a new gas cap because my old one had cracks in the o ring. I guess I'll just drive it for a bit and see if the cel turns off. Thank you for your help!

It wont turn itself off. You have to clear the codes and see if it comes back.

Hey! Just a quick update to thank you and to help anyone in the future who has a similar problem. I took your advice and bought a new gas cap for like $15. Put it on and the cel went away! So much better than the $2700 the shop quotes me for new cats lol, so thank you! I've also heard that the oil cap can cause the same code but the gas cap was the one that did it for me.

Great to hear that this worked out for you.
How the gas cap 'string' line is attached to the car body - I have a new gas cap and thought the swp to be very easy, but the nut / rivet holding the security 'string' holding the cap from falling off is still a mystery. Before braking the rivet, how I can take it out or can I?
Or is it a kind of rivet that I need a new one when replacing the gas cap?

I replaced my cap a few years ago. The rivet has a central portion that eases out of the surrounding portion. Pull it out first and then the whole thing will come out easily. You may need a trim tool or screw driver to remove the central portion.

Fantastic, thank you :cheers:

Easy: P0430 is the code for a failing main three way catalytic converter. I seriously doubt the gas cap had anything to do with it as that is not what the DME is looking at, and a gas cap failure code is completely different, usually a large vacuum leak code such as P0445, not a cat failure code.