NB Check Engine Light

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Tommys
Posts: 3
Joined: Sun Aug 28, 2016 6:45 pm

NB Check Engine Light

Post by Tommys »

Several years ago I purchased a full Roadster Sport exhaust for my 2000 Miata with a Racing Beat Header. Recently I started having the Check Engine light come on with a P0420 code (catalyst system efficiency below threshold) I have cleaned the intake and EGR and the light comes on again with the same code. Next, I replaced both oxygen sensors with OEM Denso parts and the light comes on again, same code. Then I tried one of those oxygen sensor "extensions" and drove for about 20 miles and the light did not illuminate. Took it out again later that day, and the light came on again, this time with a P0140 code (O/2 sensor circuit, no activity detected). I hate to think that the catalytic converter is defective already. I would appreciated any advice or suggestions.
Brian
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Re: NB Check Engine Light

Post by Brian »

The 99-00 typically wore the converters out faster than any other Miata generation. Typically customers needed new converters after failure of the poor design OEM ignition coils. When the coils fail or just get weak the car runs rich and burns out the converters fast. Starting with 2001 Mazda went to coil on plug design and very same converters suddenly last two or three times as long....no confidence. So, you can expect converters to live no longer than a few years on 99-00 miata as long as you have OEM ignition.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
Tommys
Posts: 3
Joined: Sun Aug 28, 2016 6:45 pm

Re: NB Check Engine Light

Post by Tommys »

Brian,
Thank you for the information. I did replace the ignition coil last year with a unit from Autozone... because it was sort of an emergency and that was all that was available.
2 questions...
1. Should I be OK with this coil, or is there a better unit available?
2. It looks like I will need to purchase a new converter from you. Will I need to purchase the 2 piece kit for $369, or do you happen to have a converter only pipe available?
Thanks Again!
Brian
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Joined: Tue Feb 15, 2005 11:44 am
Location: San Diego CA
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Re: NB Check Engine Light

Post by Brian »

Most customers stay with an OEM style Ignition unit knowing they simply need to replace them about every 50,000 miles. Only conversion to coil on plug setup will break that cycle. So, I cannot say you 'need' better as long as you understand that cycle may wipe out the converter each time. Local muffler shop near you can likely weld in new converter for you as needed every few years. Otherwise you can send entire midpipe back to our California factory and the charge is $95 for new core.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
Tommys
Posts: 3
Joined: Sun Aug 28, 2016 6:45 pm

Re: NB Check Engine Light

Post by Tommys »

Brian,

Could you give me more details about returning my mid pipe and the $95.00 core?
Thanks
Brian
Site Admin
Posts: 10620
Joined: Tue Feb 15, 2005 11:44 am
Location: San Diego CA
Contact:

Re: NB Check Engine Light

Post by Brian »

Arrange with our sales team during the week.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
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