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1998 Honda Accord LX DTC code P0420

  #11  
Old 05-03-2012, 09:02 AM
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Originally Posted by rockhoundrob View Post

One thing I wish would happen is that on this forum, it seems most people ask for advice, but rarely posts the results or solutions. If everyone would post the results of what they did, the rest of us can learn what may or may not work.

I plan to post the results, but will wait a few weeks to be sure what was "fixed" actually was fixed.
That would be great, thank you in advance.

Also you do know that in most states you can sell your old converter for $50-$75 to a recycler
 
  #12  
Old 05-07-2012, 07:38 AM
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P0420 = bad cat I got mine from NAPA fit well and works well I would use old O2;s The ECU goes thru many tests to reset the code that is way it does not come back on right away. It is not a bad job but you might need a lot of heat to remove the fastners
 
  #13  
Old 05-30-2012, 09:28 AM
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Looks like the problems are solved. *** been over a week***

1) car hestiates sometimes (about once every 10 minutes), nothing now
2) gas fume odor (not the fuel line, but smelled it right near the parts I replaced), no odors now
3) service engine light came on, with code P0420-catalytic converter efficiency below threshold. Used to come on every other day and had a rotten egg smell sometimes. Nothing for a week now....

repairs made by replacing:

Solenoid valve set... part # 17012-S84-A01
Valve (2-way) ....... part # 17371-S84-A01
Sensor Vent pressure.. part# 37940-PAA-A01
and all connecting hoses

Got the parts on the internet at Majestic Honda.
www dot hondaautomotiveparts dot com

I originally replaced these parts to get rid of the gasoline fume smell. It has been over a week and no smell, but also the check engine light does not come one any more. So I hope the catalytic converter should be ok.

The only thing that surprised me is that when I took the valves off, there was old gasoline ( dirty blackish) dripping out. I don't think this is supposed to happen since it is on the EVAP system and should only be handling fumes, not liquid.

As for why the engine light came on, I can only guess that maybe too much fuel fumes was getting into the vacuum lines due to a defective valve, causing the O2 sensor to give a bad reading thinking the CAT was going bad?

Again, thanks to everyone who gave their inputs!
 

Last edited by JimBlake; 05-30-2012 at 11:58 PM. Reason: active link
  #14  
Old 05-30-2012, 09:36 AM
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Rob - thank you for responding.

We have another member right now with a 98 that is having both evap problems and bad cat code.

He replaced the cat first only to have the code come back.

Makes me think you are on to something with your theory.

Good job and thank you for the follow-up!
 
  #15  
Old 05-30-2012, 11:59 PM
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I've bought stuff from Majestic, but since they aren't a sponsor, I have to change that link so it's not active.

About the liquid, I've heard warnings about soaking the canister with gasoline if you keep clicking the nozzle to get "a little more" gasoline when you fill up. Maybe that's what happened??
 

Last edited by JimBlake; 05-31-2012 at 12:01 AM.
  #16  
Old 05-31-2012, 12:31 AM
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I've heard the same thing Jim..could be the problem.
 
  #17  
Old 05-31-2012, 08:20 AM
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The clicking the fuel nozzle could be part of the problem. I do like to round the dollars up. If it's $26.48, I try to get it to $27.00, but I doubt less than 1 quart of extra gasoline would cause this big of a problem. I would think the canister would hold 1 or 2 quarts.

Also, the fuel smell problem should have went away after a while (at 3/4 tank or lower), but the fuel odor was a fairly persistent problem, regardless of the tank level.

If any related problem comes back, I will post here...
 
  #18  
Old 05-31-2012, 08:24 AM
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OH... I reread the original solution...need to clarify something...

When I said there was "old gasoline dripping out", it was coming out of the 2 valves that I replaced. There was no gasoline in the canister or the hoses.
 
  #19  
Old 05-31-2012, 03:42 PM
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Who is this member and how do i find his thread?

maybe i can suggest something, if i can read what the symptoms are...
 
  #20  
Old 05-31-2012, 04:22 PM
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Originally Posted by rockhoundrob View Post
Who is this member and how do i find his thread?

maybe i can suggest something, if i can read what the symptoms are...
I am referring to this thread right here.

He does not have the same code as you but has an evap code and he was thinking it was a bad cat.

You can ready about it here, perhaps you can help him...

https://www.hondaaccordforum.com/for...d-again-47284/
 

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