Hey guys, this is my first time posting here and am just looking for a little advice. I have a 98 Accord 4 cyl 5 speed and have recently gotten the CEL on my car. It has approx. 87K on it. I went to Advance Auto and they allowed me to use their tester to pull the codes. Here is what I got:

P1259 Manufacturer Control Fuel air metering
P0420 Catalyst Efficiency below threshold

I believe the first code is the MASS air sensor? and the second to be the catalytic converter?

Trouble is that I don't know if the sensors are bad or if the component is bad. Since I'm new here and the way cars are I thought I might find out that these are 2 common sensors or components that frequently go bad on the Accord and save myself a lot of headache because you all have been through them before.

Thanks in advance for any help.

 

My list says P1259 is 'VTEC system malfunction', whatever that means. Not very specific. Don't have the Helm book right here, but it'll have specific details. It could be something as simple as low oil, since there's an oil pressure switch that can interlock VTEC.

Codes above P0999 mean different things for different carmakers. Your Honda doesn't even HAVE an air mass-flow meter.

P0420 is catalyst low-effiency, they got that one right. It's measured by the 2nd O2 sensor, so it might be that sensor is bad. I'm not sure what's the best way for you to tell between a bad sensor vs. a bad cat.

Go to the fusebox in the right-side doorjamb, near the hinges. Pull out #13 for a minute, that resets the codes. If the engine light never comes back, then one or both of those codes may have been bogus or maybe stored from a long time ago.

 

Thanks Jim, I cleared the codes but the light came back on. Maybe I'll stop by there and check them again. Maybe the tester was screwed up on it because it specifically read that out to me so maybe it was a previous customers code. The tester had a scrolling readout with that message. Maybe its just the CAT since they are so known to have issues. I posted another thread about where to get a decent stock replacement CAT at if you wouldn't mind taking a look at that thread....

Thanks again.

 

Maybe after clearing, you only really have one code or the other...

The data link you plug into only transmits the code number. Any text explanation comes from the code-reader's memory. If the airflow meter stuff was on the display, that just means the code-reader was set up for a different car. P1259 probably means airflow meter on a Ford or something. Either you have to tell it what car, or else you simply read the code number & ignore the text. Anything above P0999 you gotta be careful that way.

Some places it's illegal to sell/buy used catalytic converters. In lots of years, I've NEVER had a cat fail, so my first instinct is to blame the 2nd O2 sensor. But that's not very scientific...

Try http://www.manhonda.com or http://www.hondaautomotiveparts.com?? There's some kind of sponsors list or marketplace here, too. Can you see that as a trial user?

PS... If you're gonna do much stuff with that car, go to http://www.helminc.com & get a repair manual. That's got some really specific testing & troubleshooting.

 

If your throwing a code for the cat. Its probably bad. THe 98-00 accord 4cyl. and V6's had a problem with them going bad and so did the odyssey's. The reason that the O2 sensor reads that code is because the inside of the cat has broken down and let to many phosfates get to the O2 heating element. Your best bet you be even if your not looking for performan would be to get a high flow cat and not worry about buying a factory one. If I remember correctly the factory one is some were around $700-$800. The high flow ones, if its a good one will or should still pass an emmisions inspection.

 

i think i am understanding more and more now why people get pissed when a question is asked that has already been answered... lol... i am relatively new here but i just had an elaborate conversation with Jim about this exact problem and how i fixed it.... DO THE SEARCH MAN!

 

Every message board I've ever been part of folks cry about the search feature. I will start by saying I did do a search. However, sometimes things being rehashed is good. I'd imagine every topic ever has been covered here and there really is no need for a discussion board. The boards itself could probably be locked and just make it searchable after a couple years of topics. Sometimes though new ideas can be brought about or someone might discover something new about a subject that hasn't been introduced. Get off the high horse and move along if you don't want to talk about something (again)

I will add though that my CEL went off yesterday morning. I have reset them once and it came back on but just went off yesterday. It was however, raining through the night and all day yesterday so maybe the sensor after the CAT had a short and the damp weather made a good connection. However, it is my understanding that it usually takes several trips with the sensors reading a consistant code to throw the light and the same with shutting it off so maybe it wasn't the weather. In any event I am going to pull the sensor out and try looking at cleaning it (if it can be cleaned) and make sure the connections are snug.