PO420 code and misfire
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PO420 code and misfire
2000 model with 180,000 mi.. Throwing a code PO420-Cat efficiency below threshold. This Cat is original. The car was misfiring. I changed the wires and inspected and re-gaped the plugs. The plugs were very clean and dry. The car is still misfiring. Is the misfire causing the Cat code or is a bad Cat causing the misfire?
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Re: PO420 code and misfire
I think your misfire is causing your cat to throw a code. I don't think the secondary o2 tells the ecu anything other than the fact that you're running leaner/richer than you should be. But, I'm more familiar with the 5th generation accord than your 6th so they might have advanced on the technology by 2000.
I would keep trying to trace the problem through the ignition system. How old are the plugs? This may sound silly, but are they the right plugs and are the tips distorted at all? Might be time to look into a new dizzy.
I would keep trying to trace the problem through the ignition system. How old are the plugs? This may sound silly, but are they the right plugs and are the tips distorted at all? Might be time to look into a new dizzy.
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Re: PO420 code and misfire
2000 model with 180,000 mi.. Throwing a code PO420-Cat efficiency below threshold. This Cat is original. The car was misfiring. I changed the wires and inspected and re-gaped the plugs. The plugs were very clean and dry. The car is still misfiring. Is the misfire causing the Cat code or is a bad Cat causing the misfire?
although, i guess the cat could be slightly plugged and restricting the exhaust flow which could lead to a misfire if too much of the exhaust is staying in the cylinders. i would unbolt the cat and take a look inside it. may be time for a cat.
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