Bad Catalytic Converter

[mjquillici]

My dad has a 2004 4Runner. Apparently he is throwing a check engine/VSC light. Both the dealer and our local shop are claiming that the second of the two (it has two?) catalytic converters is bad.

I'm having a hard time wrapping my head around this. Why would a catalytic converter go bad? That doesn't make any sense to me. I'm convinced that it must be an oxygen sensor, but I guess he was told by two different shops that it's definitely the catalytic converter.

Does anybody know what could be going on?

 

[Chaz526]

Cats can eventually lose their ability to function properly, but before replacing it, I'd try replacing the O2 sensors to see if the code persists. Remember that shops and especially dealerships tend to claim the more expensive part needs to be repaired/replaced.

 

[awdjunkies]

Cats can eventually lose their ability to function properly, but before replacing it, I'd try replacing the O2 sensors to see if the code persists. Remember that shops and especially dealerships tend to claim the more expensive part needs to be repaired/replaced.

Great advice.. But before purchasing anything how about the codes it is throwing? does he have a v6 or v8?

 

[BlackWorksInc]

My dad has a 2004 4Runner. Apparently he is throwing a check engine/VSC light. Both the dealer and our local shop are claiming that the second of the two (it has two?) catalytic converters is bad.

I'm having a hard time wrapping my head around this. Why would a catalytic converter go bad? That doesn't make any sense to me. I'm convinced that it must be an oxygen sensor, but I guess he was told by two different shops that it's definitely the catalytic converter.

Does anybody know what could be going on?

Give this a read as it will help explain things a bit better.

Also you have 4 Catalytic Converters, 1 built into each manifold and 1 after each manifold.

 

[matuszyk]

A catalytic converter works using platinum as a catalyst. Precious metals are extremely unreactive (i.e., they do not corrode) by nature. I have seen some claims that if the catalyst is not physically damaged, it is generally gunked up by the bi-products of the combustion process. There are claims that one can chemically clean them and go back to using it. I often wonder if that would be time effective.

 

[mjquillici]

VSC Zero-Point Calibration

After the check engine light was re-set at a local shop, the VSC TRAC and VSC OFF lights were still illuminated. I did some searching and found this gem. It worked perfectly.

https://www.youtube.com/watch?v=55XmiSsGQgo

 

[MikeInNH]

Why would a catalytic converter go bad?

They usually don't. And they are usually the most misdiagnosed part on today's cars. The ECU is telling you that it's getting a bad reading from the O2 sensor. So it's either a bad O2 sensor (most likely), or a bad CAT. Some mechanics replace the CAT and O2 when all that was needed was a new O2 sensor. Start with a new O2 sensor...if it's still failing..then you'll need a new CAT.

 

[earthrealm]

After the check engine light was re-set at a local shop, the VSC TRAC and VSC OFF lights were still illuminated. I did some searching and found this gem. It worked perfectly.

https://www.youtube.com/watch?v=55XmiSsGQgo

did you by chance send a wrong youtube link?. whats on the link you send is how to do zpc and clear vsc lights.

do send the correct link please, am having similar issue, however my codes alternate...sometimes both CAT codes...sometimes both 02 sensor codes

 

[MikeinNH67]

8 year old thread, you probably won't get an answer.

 

[AuSeeker]

did you by chance send a wrong youtube link?. whats on the link you send is how to do zpc and clear vsc lights.

do send the correct link please, am having similar issue, however my codes alternate...sometimes both CAT codes...sometimes both 02 sensor codes

8 year old thread, you probably won't get an answer.

Not only is the topic 8 years old, but also the member that was quoted hasn't been on the forum since 2015, 10 days after he posted.