mschumacher

Accord with 133,000 miles. Check engine light on. Reset the code and it comes back every two days. Checked with a scan tool. Scan tool reads a P0420 which the Helms service man states is Catalytic system efficiency below threshold. Helms says to check the Catalytic converter, how? Do I need to replace my three way Catalytic converter? My exhaust is in good shape, I dont want to tear it up. Any advice on where to get a converter? Could the primary or secondary HO2S be the cause. They are still original.

iam7head

the way to check the cat is simple, get a hold of a laser heat reading gun, the gas going in to the cat should be around 500degree, take that number and add 50 more degree after the cat, if the number is less then before, your cat's toasted

I am not sure about the code tho'

honda seel those around 2-3 billz

nuc79

I've got the same code on my 99 Odyssey w/102k. From what I found on http://www.odyclub.com, everyone else that had the same code on theirs had the cat replaced and it fixed the problem.

Also I've been getting a PO401 EGR code, but that's a known problem in the 99-01 J35A V-6, and I'm just lucky enough to be out of the 8yr/80k EGR warranty extension.

i'm assuming you have the V6 accord?

You can get a stock cat from http://www.all-catalytic-conve....html for $172.20 w/ free shipping and a 5/50 warranty.

Or get a test pipe or hi-flow unit (or punch out your old worn-out one) and get a O2 sensor simulator for $40 from http://www.accordinglydone.com

fast93accord

With the code P0420 (catalyst deterioration), we will replace the cat, and the secondary oxygen sensor, and clear the code.

mschumacher

Thanks for the info. With 133,000 , should I replace the entire exhaust? What causes the Cat conveter to go bad? , cheap gas? , too rich?, The car runs fine?

Elvis1977

My 98 accord had 90k miles when cat read 420 code. Sorry you Have to replace the converter. Many people are experiencing similar problems with the cat on these 6 generation accords. Fortunately i convinced a honda dealership to cover the part under warrenty, but had to pay for the labor. DON'T USE AFTERMARKET!!!!!

nuc79

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Elvis1977 &raquo;</TD></TR><TR><TD CLASS="quote">DON'T USE AFTERMARKET!!!!!</TD></TR></TABLE>

Funny you should mention that. I was completely astounded that there was even an aftermarket one available for our van. So much, even, that I called the 1-800 number for http://www.all-catalytic-converters.com and spoke to them about it. Turns out that they get the Odyssey ones from the same OEM supplier that Honda uses. I don't know if this is true for the Accord, but IMO, I'll be buying the same one for half the price with a better warranty. Makes sense to me.