Check engine light Stays on

Getting a PO421 code? Is this a bad CAT? Car is sonata 2002 with a 2.4L with 94k miles. In the last 3,000 miles have had tune-up,new timing chain,new water pump.I understand CAT are expensive for this type of vechile.

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Reply to
Travelsmart
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Most likely, yes, you need a manifold catalytic converter. Check for exhaust leaks and proper oxygen sensor operation. If oxygen sensors are working properly and there are no exhaust leaks, replace the converter.

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Reply to
hyundaitech

Lucked out new gas cap did the trick. Happy Holidays

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Reply to
Travelsmart

A new gas cap won't cure a P0421. What makes you think you've fixed the problem?

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Reply to
hyundaitech

After looking back, I see the tone of the previous post appears abrasive. It wasn't meant to be. I am indeed interested in why you believe the car is fixed. Did the lamp go out? Did you turn it out and it didn't come back on?

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Reply to
hyundaitech

Lamp went out and hasn't come back on.

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Reply to
Travelsmart

Lamp went out by its self and has not come back on.

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Reply to
Travelsmart

Chances are your catalytic converter is at marginal efficiency. The lamp will probably come back on sooner or later, with the same code.

Since it went out on its own, disconnect the negative battery terminal for about five seconds to clear the code (presuming you're outside the 8/80 warranty period). If you're still within the warranty period, present the car to the dealer for service, hopefully while the code is still present in memory.

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Reply to
hyundaitech

I'll keep you posted. Foot Note: Local newspaper article said certain individuals are stealing CAT for metal value?Some can be taken within minutes.

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Reply to
Travelsmart

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