The P0430 code was logged in my ECU this week.

After reading a number of posts on the P0420/P0430 and O2 sensors, I am bit confused when the code itself talks about the efficiency of the catalytic convertor.

How often is this code associated with failing O2 sensor and not actually a failing/failed converter?

I have 85K miles and more often there have been threads that the O2 sensors have been replaced. Would it be premature to think a catalytic converter would have failed?

Any suggestions would help.

 

I have the same code ... my obd - II has the 02 sensors at -- .8 .3 .8 .3 respectively - if that makes sense. So i think thats normal voltage for 02sensors - My car also dies when i rev it and let RPMs dropp - I did the MAF unplugged test and she idles like a champ - Im thinking the MAF went bad, causing rich mixtures - which caused the Cats to fry ? or it's just the 150K on my car.

PS ive heard of Cats frying at 40k with these cars - so it could be your cat - i beleive the 02 sensors throw their own codes...

 

I thought so too, that the MAF was sending rich mixtures that were not completely burned. It beats me why wouldn't the stupid MAF spit out a code. What costs $100 to replace may result in replacing the cats which go in excess of $1000 (parts + labor).

Bloody morons who designed this car, the least tell us that the MAFs have to be replaced every 60K which I can gladly do (just like the coils that almost every one have replaced), than having to replace the cats and inadvertently put leak out between the Y-pipe and the cats.

 

Well put - Not sure if the rich mixtures will burn out the cats - at this point i don't care : ) But - i would like to find out how (if at all ) i can replace that front pre-cat, or eliminate it (Cali spec 2 front pre-cats and one main ) - I'm gonna try running higher octane fuel and check the OBD2 again to see if i am running a bit leaner ? or if the timing changes - 13 deg. right now i- i'd like to see it a bit higher - maybe using low grade fuel will cause the engine to run richer and retard timing - causing burnt out cats...

my biggest problem will be finding out how to replace that front pre- cat ( if it cant be eliminated ) without going to the stealership - they quoted 565 dollars for the part alone >.<

 

Call Redmax at Redlinemax.com. For that price you should be able to get a new Y-pipe. BTW: mine threw the same code when I fried my cat on my 03. See my "3.5 oil consumption: Fixed" post. You may be experiencing the same crap I did.

 

If you have cali specs and never had a ECM reprogram then that might be what you need.

 

0430/0420 are catalyst efficiency faults, both pre and post cat o2 sensors have to be working properly to throw those codes, if the rear o2 is cycling like the front o2, the ECM will throw with code, depending on bank.

diagnose lean/rich conditions and check for exhaust leaks before focusing on the cat fault.

 

ok - car does run very rich - black deposits after about 50 miles of driving on the plugs - can a bad MAF cause this? Im assuming so because thats what meters incoming air - and the MAF unplugged testf gave me a strong idle again -


thanks bewst