rjh4us

I bought a 2003 Honda Civic Hybrid with 108 k miles. The engine light just came on with P1420 code. Honda dealership suggests I may have to change the Catalytic Converter. and perhaps O2 sensors. There seem to be 2 Cats and two O2s. All these are very expensive. any suggestions?

It Wasn't Me

Was P1420 the only code that showed up in the scan? If not, we need to know the other codes that were displayed.

If P1420 was the only code, do the following.

1. Reset the ECU. (remove fuse #6 (15 amp) from the under hood fuse box. Wait a minute before reinstalling it)

2. Start the engine. With the car in Park or Neutral, raise and hold the RPM at 3,000 until the radiator fan comes on.

3. Raise the RPM to 4,000 for about ten minutes.

4. Test-drive under these conditions:
- Maintain a speed of 55 - 65 MPH with the CVT in D position (M/T in 4th or 5th gear) until the readiness code or Temporary DTC P1420 is set.

5. Check for a Temporary DTC by scanning the car again.
- Is Temporary DTC P1420 indicated?
Yes - Check the NOx adsorptive three-way catalytic converter. If necessary, replace it.
No - Intermittent failure, system is okay at this time.





If you need to replace the TWC (three-way catalytic converter) I suggest buying one online. It's a lot less expensive than buying one from your local dealership.

Go here: http://www.hondaautomotiveparts.com/

Also ask if your local dealership will match the (shipped) price from Majestic Honda. If they won't match the price, buy it online from Majestic and install it at home.

rjh4us

Thanks very much. I will follow your instructions and advise results.

rjh4us

I followed steps 1 thru 4. The engine light had already gone off. I drove about 20 miles at 55 - 65 mph. All looking good for now. Hoping that it will stay that way. Thanks very much for your help.

rjh4us

--------------------------------------------------------------------------------

I followed steps 1 thru 4. The engine light had already gone off. I drove about 20 miles at 55 - 65 mph. All looking good for now. Hoping that it will stay that way. Thanks very much for your help.

varmint

This story mirrors my own- 2003 hybrid, 100100 miles, emissions light came on, P1420 code, dealer tells me they need to replace the converter. I had them reset it, and ever since, no more warning light.

I looked into this, and learned there are two converters, and that oxygen sensors tend to be problematic. They seem to think it is the front converter that needs to be replaced. We had a sensor replaced at 50,000 miles, under warrantee. My question is this: is it likely that the front cat is bad, and is there a way I can watch for bad sensors? I plan on getting an OBD-2 reader, since without one, you can't do much, and paying the dealer one time cost about as much as buying one.

The NOx 3way adsorptive converter was mentioned as the one to replace, but for novices like me, which one is that???

My wife loves this car, and plans to drive it as long as it works well, but right now, I'm worried about spiraling maintenaince costs! I had just replaced the spark plugs (with OEM plugs) 3000 miles ago, and otherwise, the car seemed good to go. We've averaged about 48mpg over the first 100k miles.

Thanks!

It Wasn't Me

It's under the car.

Worry about the sensors if you throw another code. Sensors will usually throw a code of their own, but that's not always the case.


Also, you can have your car scanned for free at many auto parts stores. (Auto Zone, Pep Boys, etc)

varmint

Thanks! I did a little more oneline research, and discovered, at an aftermarket manufacturer's website (Davico) that the rear, or under car as was noted, cat is the NOX absorptive converter. Plus, since thge sensor that would read the performance of the cat is behind that one, it makes sense to me now that this is the bad convertor? I ordered this OBD-II reader from amazon:
http://www.amazon.com/Equus-3030-Inn...pr_product_top

since it makes more sense to me to be able to see what's going on without being at the mercy of someone else's kindness, or worse, greed.

The light is still off, but I don't expect that to remain.

It Wasn't Me

No problem.


Well, good thing the light is still off. Hopefully it stays that way for awhile. Catalytic converter replacement is rather costly.


Good luck with it!

Motonari

IWM, you certainly know a lot about Hondas! Here's a new one: '03 HCH, 170k miles - EMA and check engine (P1420) lights come on at the same time. Dealer says I need new battery pack and CatC. Can't afford at the time (they want $1,300 deposit to order batter pack) so I leave. Two days later the EMA light goes out. Week later the check engine light goes out. This recurs throughout the summer. Now only the EMA light turns off and on. Need to drive with my scanner hooked up. Thoughts? Seemed like an intermittent electrical issue; now I'm not so sure. Thanks!

It Wasn't Me

Literary guidance. There's plenty that I don't know.

EMA? Do you mean IMA? Sorry, but I'm not familiar with the Hybrid Civics. Hardly anyone here has one, so information is sparse.

Have you tried the steps I listed above? It's worth a shot.

If it's an intermittent issue, I wouldn't worry about it too much, but I would not completely ignore it either. After doing some reading (on hybrid car forums) a lot of people seem to have the same phantom issues with the P1420 and IMA lights. After spending an arm and a leg at the dealership, the problems continue.



The P1420 also seems to be an intermittent issue since it has not come back. You should expect that it eventually will, though. Were there any other codes stored in addition to the P1420? Or is that all the dealership was able to retrieve?

Sorry I couldn't be of more help.

Motonari

Don't know what happened but I couldn't log back in. Thanks for the prompt reply and you're correct, that was IMA. The previous owner must have had the same issue as a new catalytic converter was installed in 2008. Other codes were P1600 and P1445; all non-generic.

justinsbg

I don't know if you were aware of this but there is a service bulletin out by Honda that explains a ECM update to correct the malfunction threshold for the converter. On some Hybrid Civics there is also an update for extending the battery pack life. I don't remember the specifics but I would go to your local dealership where they have the proper equipment to update your vehicle's computer.
Service Bulletin
© 2011 American Honda Motor Co., Inc. – All Rights Reserved ATB 46767 (1108) 1 of 2
CUSTOMER INFORMATION: The information in this bulletin is intended for use only by skilled technicians who have the proper tools, equipment,
and training to correctly and safely maintain your vehicle. These procedures should not be attempted by “do-it-yourselfers,” and you should not assume
this bulletin applies to your vehicle, or that your vehicle has the condition described. To determine whether this information applies, contact an
authorized Honda automobile dealer.
August 17, 2011
11-043
Applies To: 2003–05 Civic Hybrid ULEV (KA) – Check the iN VIN status for eligibility
Product Update: ECM Update to Improve DTC P1420 and P2000 Detection
ThresholdBACKGROUND
When the NOx adsorptive catalytic converter is hot, the
PGM-FI software can misinterpret the signal from the
secondary heated oxygen sensor, and may incorrectly
indicate that the catalytic converter is deteriorated. The
software update improves the accuracy of the catalyst
deterioration detection.
NOTE: American Honda is also extending the warranty
on the secondary and third heated oxygen sensors. For
more information, refer to Service Bulletin 11-044,
Warranty Extension: Secondary and Third Heated
Oxygen Sensors.
CUSTOMER NOTIFICATION

lovemyhondahybr

Oh my goodness. I cannot begin to tell you all how excited I am to have FINALLY found information on this OBD2 code! My check engine light turned on in March so I had it shut off, it turned back on then shut off by itself a week later. It came on once over the summer and shut off by itself. Last week it turned on so I had it shut off and sadly it turned back on last night. The car seems to be running perfectly so I am not too worried about it having any issues but I don't want it to damage my car! I love my hybrid! I am having it checked out by my mechanic on Tuesday of next week. I can't afford a $2000 repair bill so I hope it's just a sensor!

varmint

Very interesting about the dealer info- reprogramming the ECM. The light came back on after being off for a couple of months, while I was driving on the highway again for more than 25 or 30 minutes (actually, the same trip path that had triggered it before!) and I reset it again. This indicated to me that it took that long at high speeds to trigger the malfunction indicator.
FWIW, I was talking with a car buddy of mine shortly thereafter, who simply suggested running a can of SEAFOAM fuel system cleaner thru the gas tank. It seems that this often solves problems with sensors, by cleaning them. Well, we've now driven several thousand miles since doing that, much of it at high speeds over hundreds of miles (well, 70+ mph) and in warm weather, and that check engine light hasn't come back on. Maybe the cleaner did the trick? If it comes on again, I will check with a dealer about the ECM.

pgoldilla

I recently changed my oil and used Lucas Oil additive in my 2003 Honda Civic Hybrid. Could this have caused the check engine light to come on or actually damage something?

Rick hybrid

a better product to use is redline fuel system injector cleaner. Lucas oil products get bashed on the bob is the oil guy forums.
also try http://www.greenhybrid.com/discuss/f12/