Honda Accord Forums - The DriveAccord community is where Honda Accord 2003+ owners can discuss reviews, service, parts, and share mods. banner
Cancel
Create thread New Garage Forums

P0420 Code

Jump to Latest
1 - 20 of 21 Posts
J

jweston01

· Registered
Joined
·
5 Posts
Reaction score
0
Discussion starter · #1 ·
Hi. A week ago I purchased a 2003 Honda Accord EX with 155,000 Miles on it. I love the car, however last night I had the MIL come on. This morning I ran the codes at AutoZone and it registered a P0240 Error. My Accord is a 4 cylinder, Manual Trans., and just a LEV NOT ULEV.

A few things I have questions about that I am hoping you all can help me with; thank you in advance.

Right before driving the vehicle I put Windshield wiper fluid in the reservoir and spilled quite a bit of it around that area. Could this have triggered such an error by chance?

I am fairly good with working on my own vehicles however I want advice on what my next step should be. The Code suggests the following:

"Catalyst System Efficiency Below Threshold (Bank 1)
- A/F Ratio Concern
- Air Leak Near HO2S (Heated Oxygen Sensor) (Bank 1)
- Ignition System Concern
- Faulty Catalytic Converter"

Is there anyway to reset the light and perhaps see if it comes back on again?
Would a cleaning agent such as Seafoam possibly resolve the problem?

I really appreciate any help with this matter and apologize for the lengthy post.

EDIT: Also, could this be something to do with the Service Bulletin "03-063". Please see attached.
 

Attachments

#2 ·
If you search "p0420" in the 7th gen section there are a total off 22 threads to read through. If you search it in "the honda accord lab" there are 28 threads. I imagine at least one of those threads will help.

jweston01 said:
Right before driving the vehicle I put Windshield wiper fluid in the reservoir and spilled quite a bit of it around that area. Could this have triggered such an error by chance?
Click to expand...
I really doubt it since p0420 is more of an internal code. There is another code that has more to do with the wiring of the 02 sensor.


jweston01 said:
Is there anyway to reset the light and perhaps see if it comes back on again?
Click to expand...
I would ASSume that autozone cleared if after they checked the code. They do this most all of the time.


jweston01 said:
Would a cleaning agent such as Seafoam possibly resolve the problem?
Click to expand...
I doubt it, and it may make it worse.
 
Discussion starter · #3 ·
I appreciate your prompt response. They did not clear the code and the light was still on when I drove it home this morning. Is there anyway I could clear it myself?

Thanks again for all your help.
 
#5 ·
jweston01 said:
Hi. A week ago I purchased a 2003 Honda Accord EX with 155,000 Miles on it. I love the car, however last night I had the MIL come on. This morning I ran the codes at AutoZone and it registered a P0240 Error. My Accord is a 4 cylinder, Manual Trans., and just a LEV NOT ULEV.

A few things I have questions about that I am hoping you all can help me with; thank you in advance.

Right before driving the vehicle I put Windshield wiper fluid in the reservoir and spilled quite a bit of it around that area. Could this have triggered such an error by chance?

I am fairly good with working on my own vehicles however I want advice on what my next step should be. The Code suggests the following:

"Catalyst System Efficiency Below Threshold (Bank 1)
- A/F Ratio Concern
- Air Leak Near HO2S (Heated Oxygen Sensor) (Bank 1)
- Ignition System Concern
- Faulty Catalytic Converter"

Is there anyway to reset the light and perhaps see if it comes back on again?
Would a cleaning agent such as Seafoam possibly resolve the problem?

I really appreciate any help with this matter and apologize for the lengthy post.

EDIT: Also, could this be something to do with the Service Bulletin "03-063". Please see attached.
Click to expand...

Well based on what you had said, i have to say, that it sounds like whomever sold it to you did the "battery disconnect" trick, to shut off the check engine light. If thats the case, all of this stuff was wrong from the previous owner, and now that a week went by, the codes are reading like this again...WHo did you buy it from?
I had the CEL light go on for my car 2 weeks after i baught it, but it was just a sensor in the radiator...part cost 20$
 
#6 ·
jweston01 said:
They did not clear the code and the light was still on when I drove it home this morning. Is there anyway I could clear it myself?
Click to expand...
That is surprising. The easiest way is to remove the negative terminal from the battery for at least ten minutes. Make sure you have your radio code befoer doing it though.

Another way IIRC, there is an ECU fuse in the engine bay and you can pull that, turn accessories on for a minute or two, turn it off, and replace the fuse. I think that's the way it goes. :dunno:
 
Discussion starter · #8 ·
scar_cle I bought it from a local honda dealership here. I do not think I am protected by any scam laws given that I do not have proof that they erased the code temporarily. I am going to get it checked out on Friday and see what the next step is? Is there a possibility that driving it could hurt until then? Thanks again.
 
#9 ·
A lot of misinformation in this thread...

First, reset the code and see if it comes back. if it does, then you have some trouble shooting to do.

If the code comes back, I would start at the spark plugs and coils. make sure the plugs look clean (ie no black build up, not oily, and correctly gapped) plugs tell you alot about the health of your engine.
If everything checks out there, check fuel pressure.
Then check for exhaust leaks.

The car is in the range for a catalytic converter replacement but that doesnt mean you should just jump right to it if your car has another issue.

Second, Autozone does not reset any check engine light. All employees are vehemently told NOT to do so.

Third, to the OP you arent covered under any scam laws unless you can prove the car was tampered with. You purchased the car as is with no warranty. If the dealer wants a repeat customer you might go back and see if they will work with you on it. but its a long shot.
 
Discussion starter · #10 ·
AT93 said:
A lot of misinformation in this thread...

First, reset the code and see if it comes back. if it does, then you have some trouble shooting to do.

If the code comes back, I would start at the spark plugs and coils. make sure the plugs look clean (ie no black build up, not oily, and correctly gapped) plugs tell you alot about the health of your engine.
If everything checks out there, check fuel pressure.
Then check for exhaust leaks.

The car is in the range for a catalytic converter replacement but that doesnt mean you should just jump right to it if your car has another issue.

Second, Autozone does not reset any check engine light. All employees are vehemently told NOT to do so.

Third, to the OP you arent covered under any scam laws unless you can prove the car was tampered with. You purchased the car as is with no warranty. If the dealer wants a repeat customer you might go back and see if they will work with you on it. but its a long shot.
Click to expand...
Will do after class today. And let you know what I find. In regards to the attachment I posted, could that be the culprit? Is it worth a shot looking into?
 
#11 ·
AT93 said:
Second, Autozone does not reset any check engine light. All employees are vehemently told NOT to do so.
Click to expand...
Maybe where you live they don't but I called a local one and they said "yes, we will reset the CEL for you."

jweston01 said:
In regards to the attachment I posted, could that be the culprit? Is it worth a shot looking into?
Click to expand...
That TSB is from 2003 about a year after the cars were released. It looks to be an ECM/PCM software problem. It's possible that could be the problem, but I think it was aimed at "new" cars that needed the ECM/PCM updated.
 
Discussion starter · #12 ·
Good to know. Thanks for the info. Will attempt to manually reset CEL today and see if that brings any good news. If not will follow up on here and start with the steps you provided earlier. Thanks again.
 
#13 ·
jweston01 said:
Good to know. Thanks for the info. Will attempt to manually reset CEL today and see if that brings any good news. If not will follow up on here and start with the steps you provided earlier. Thanks again.
Click to expand...
I haven't really helped much. AT93 gave more info than I did. :thmsup:
 
#14 ·
jweston01 said:
Will do after class today. And let you know what I find. In regards to the attachment I posted, could that be the culprit? Is it worth a shot looking into?
Click to expand...
Definitely worth a look, dealer should do it for free. its just a software download off a scan tool. Its a long shot that it hasnt been done, if you arent the original owner.
 
#15 ·
sodaks2k said:
Maybe where you live they don't but I called a local one and they said "yes, we will reset the CEL for you."
Click to expand...
It has to do with emission testing. It doesnt mean that it doesnt happen under the table but it is a company policy not to reset it. I have worked in AZ and I have seen "tips" after "reading" CELs.
 
#16 ·
Save
Reply Quote Like Like
#19 ·
sodaks2k said:
We don't have emmision testing here so that's probably why they're "allowed" to do it.
Click to expand...
ahhh how nice it would be to live in a red state...
 
Save
Reply Quote Like Like
1 - 20 of 21 Posts
About this Discussion
20 Replies
9 Participants
Last post:
sodaks2k
Honda Accord Forums - The DriveAccord community is where Honda Accord 2003+ owners can discuss reviews, service, parts, and share mods.
posts
2.1M
members
146K
Since
2003
Drive Accord forum, a community where Honda Accord owners can discuss reviews, service, parts, and share mods.
Full Forum Listing
Explore Our Forums
The 8th Generation The 7th Generation The 9th Generation The 10th Generation Audio, Electronics & Lighting