# Service engine light soon!!! Cat converter??



## 91 3sgte (Sep 19, 2003)

Hey guys, I have a 00 GXE and the SES light just came on! Anyway, I took it to Autozone to see what it was and when they hooked up the diagnostic tool, they told me that it was the Catalytic converter. I have 70k miles on it and was wondering... could it be the 02 sensor in the Cat? or is it the Cat itself? What do u think guys?


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## Mr SEntra (Oct 7, 2002)

*Hmm......*

Hmm....it if was the O2 sensor, then it would have came up that way. Cat converters are kinda expensive, but maybe it really has gone bad. I wonder how OBD II figures that out. It might be the fact that the O2 sensors are reading bad readings at the 2nd O2 sensor and both sensors are working fine.


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## sr20dem0n (Mar 19, 2003)

It could really be either the cat or the o2 sensor

I won't go into the details right now as I have a class in 3 minutes, but I'll explain further when I get back


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## Mr SEntra (Oct 7, 2002)

sr20dem0n said:


> *It could really be either the cat or the o2 sensor
> 
> I won't go into the details right now as I have a class in 3 minutes, but I'll explain further when I get back *


NP man, I was just throwing out ideas. Wouldn't it come up with an O2 sensor code though if it was a faulty sensor?


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## 91 3sgte (Sep 19, 2003)

Thanks for the replies guys... I took it to another Autozone and the same code came up... However, this time the guy said it was related to the O2 sensor and that it was the first bank. Whaddya guys think? Which O2 sensor would that be - the first bank?


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## sr20dem0n (Mar 19, 2003)

Mr SEntra said:


> *NP man, I was just throwing out ideas. Wouldn't it come up with an O2 sensor code though if it was a faulty sensor? *


well it depends on how it's reading

If the o2 sensor isn't sending any signal at all then it would come up as a problem with the o2 sensor. If the sensor is sending the wrong signal then the car will think something must be wrong with the cat and it will come up as a cat problem.

As for the first bank o2 sensor....I have no idea. I would call the dealership and ask what that means.


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## Mr SEntra (Oct 7, 2002)

Definitely call the dealership first, but I would say the first bank is the first downstream. That's weird though.


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## johnk (Apr 30, 2002)

What was the code?


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## 91 3sgte (Sep 19, 2003)

I have no idea what the code was... the guy at autozone hooked it up to one of those actron OBDII tools. BTW... the service engine light went away!? What does this mean?? It fixed itself??? what do u guys think?


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## Mr SEntra (Oct 7, 2002)

91 3sgte said:


> *I have no idea what the code was... the guy at autozone hooked it up to one of those actron OBDII tools. BTW... the service engine light went away!? What does this mean?? It fixed itself??? what do u guys think? *


It could be an intermitten problem, but I don't think so if the light automatically goes out......


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## sr20dem0n (Mar 19, 2003)

maybe it was a bad batch of gas and the o2 sensors were picking up some funky things in the exhaust and the ECU just assumed it was the cat?

that was a shot waaaaay out into left field, I'm pretty much rambling to myself, pay no attention


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## 91 3sgte (Sep 19, 2003)

sr20dem0n said:


> *maybe it was a bad batch of gas and the o2 sensors were picking up some funky things in the exhaust and the ECU just assumed it was the cat?
> 
> that was a shot waaaaay out into left field, I'm pretty much rambling to myself, pay no attention  *


Hey man, that could be right? Cuz it hasn't turned on again!!! Hopefully it'll stay off... maybe from now on, i'll stick with premium!!!


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