code p0421 and p0421
anusemoon
08-22-2004, 03:07 PM
what do these codes mean.....
p0421 and p0421 ( warm up catalyst efficency below threshold ( bank 1 and 2 ) 98 millenia failed emission test how can i fix this???
p0421 and p0421 ( warm up catalyst efficency below threshold ( bank 1 and 2 ) 98 millenia failed emission test how can i fix this???
anusemoon
08-22-2004, 03:08 PM
P0421 and P0431
dsatt12
08-23-2004, 02:38 AM
That's not very nice... now I had to go learn all about Miller cycle engines.
As for your question, there are lots of Mazda boards I found with info on this. You need to check with your dealer and see if your Millennia needs the PCM reflashed (they'll run your vin# and check). This is purported to fix 80-90% of the P0421 codes. Beyond that, you've either got a bad catalytic convertor or bad O2 sensors it sounds like.
Now hope your supercharger doesn't go out on you to the tune of $7000 for a new one. I thought Auroras were bad...
As for your question, there are lots of Mazda boards I found with info on this. You need to check with your dealer and see if your Millennia needs the PCM reflashed (they'll run your vin# and check). This is purported to fix 80-90% of the P0421 codes. Beyond that, you've either got a bad catalytic convertor or bad O2 sensors it sounds like.
Now hope your supercharger doesn't go out on you to the tune of $7000 for a new one. I thought Auroras were bad...
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