P0421 Code Help?

[revomatic]

I have a 2002 protege5 wagon & my light came on do to a p0421 code. Should I just replace the cat. Or is there something else I should do. This is my First Mazda & everything is new to me. I also had a p1250 code but I found that's an easy fix? Does that relate to the 0421 code by any chance?

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[rsvinylgraphics]

A code P0421 may mean that one or more of the following has happened:

* The catalytic converter is no longer functioning properly
* An oxygen sensor is not reading (functioning) properly
* A sparkplug is fouled up

As for the p1250 code:

https://www.youtube.com/watch?v=ucOq-83Hv2Y

 

[revomatic]

Thank you


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[revomatic]

I've seen that video it's an easy fix. Just want to fix that other code & keep the car stock as possible with no short cuts here in NJ we have inspection & the do a visual look at the cats


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[concept]

You might want to read this mechanic's story before you replace anything:

http://www.askamechanic.info/askamech2/content/view/29/47/

 

[sparkybuoy]

this is caused by a STICKING THERMOSTAT causing the engine not to warm up fast enough