My wife has an 05 Pilot, it has about 120,000 miles on it and the p430 code has pooped up on it twice in the past 2 weeks. I have a cheap code reader, I pulled the p430 code, then erased it, but came back a week later, I need to fix this, it's due a smog check in Aug. From that code I get a "bank 2" reference. Can someone tell me where the o2 sensors are, it is a 6 cylinder, 3.5 I think, where is "bank 1", "bank 2", and are there actually 3 o2 sensors?? One on each exhaust manifold, and one after the cat??? I have a friend who says I should just replace them all because after just changing one, I'll end up back under it changing the others very soon after....So I'd appreciate any help, with the code, and what you suggest on the "fix"..
Thanks, Gary G.

 

There are four sensors . Two are pre cat (af sensors) and the other two are post cat 02 sensors . Bank 2 is the cat directly behind the radiator . Those cats are not cheap ! You should also replace the shields when doing this as they always rot out . So in summary you need a new cat and shields and it wouldnt be a bad idea to replace the secondary 02 sensor (post cat) .

 

So you're saying i need to replace the cat. and not an o2 sensor? The shield should be OK, I'm in southern California.. So Bank 2 is closest to the radiator. Have you seen this code before, p430? This sounds like it's going to be expensive.....
Gary G.

 

Yes ive seen this before . If youre in Cali then the shield should be fine . The cat is more than likely the problem . Replacing the secondary 02 sensor is not needed but not a bad idea .

 

Now I'm trying to find a replacement cat, I can find several on the net, around $275 but they "will not ship to a California" or "49 state legal"....... I don't want to go to the dealer, I'm sure their price is crazy high.... Any suggestions?? I have seen on the internet people " cleaning" their cats, one guy says to put a gallon of lacquer thinner into a half tank of gas, then drive at high speed for about 150 miles, or run the car at like 2000 rpm for 30 minutes....I guess this mixture will burn very hot and "clean" out the cat...... Cheaper than buying a new cat, which is turning into a challenge out here in CA...I may call afew muffler shops, and the car is due a smog check right now for DMV renewal, so I need to get this taken care of. I have changed both before and after O2 sensors for bank 2, closest to the radiator, I clear the code but it comes back in a few days...
Gary G.

 

Youre SOL. There are no CA approved aftermarket cats available for the Pilot. You HAVE to buy it from the dealer.(around $250-$300) As for cleaning out the cat, it is bullshit. Cats do not get dirty, the material deteriorates over time, and no amount of "cleaning" will bring them back. As for changing the O2's, some one already told you not to. Well they do eventually wear out, so its not a total waste of money, however you needlessly spent money when you should've just bought a cat.

 

I had a local tech steer me in the wrong direction........Car has over 120,000 miles on it, of the ones he worked on, the sensors fail around this milage, and not the cat..
Gary G.

 

p0430 / p0420 doesn't always mean a bad catalyst.

catalyst efficiency needs to be monitored with a scan tool that can display O2 sensor data. You can then determine if indeed the catalyst is failing or if its just a lazy or unresponsive O2 sensor.

 

Unlikely. The code criteria is pretty strict. Outside influence(exhaust leak, rich or lean running condition, etc..) will most likely set a false cat code. The PCM will test the response of the rear O2 by forcing a rich and lean condition, if the rear O2 is unresponsive or slow, you will get an O2 sensor code in addition to a cat code.

 

You cannot monitor cat efficiency. Cat efficiency is determined by a series test carried out by the PCM and ultimately comparing the locus. You can only monitor the Cat Monitor for completion. AF sensors are NOT O2 sensors.

 

who said anything about AF sensors? a simple code reader won't be able to pull data monitoring, but with any decent scan tool you will be able to get a waveform of the rear O2 sensor. If there is rapid voltage fluctuation you can be pretty damn sure the cat isn't doing its job.

 

Wrong.

 

Wow youre still fighting this issue . Just put a cat in it and be done . I dont know much though ive only been working on Hondas for 17 years .....

 

Right.

 

No son you are wrong. Modern Hondas use the rear o2 to trim and it is never in a static position. It will fluctuate just like a pre cat o2 would, and is not indicative of a bad cat. On this model the pre cat sensor is an AF sensor. AF sensors do not measure in Mv like O2 sensors do, so even if you were to try to attempt that foolish, rookie test of yours the results would be inconclusive. Get educated kid, I do this ****.....

 

I was on vacation for a week, and I just haven't had time to get the California legal Cat, and stuff it in..........
Gary G.

 

funny thing is I agree with what you're saying. but I feel like we're not quite on the same page. again - I'm not referring to AF sensors.

rear O2 sensors should indeed fluctuate, but it should do so quite slowly - switching from rich to lean over several seconds.

now - if you were to see rapid fluctuation of the rear O2 sensor (1-2 seconds) what would you conclude? No cocky sarcastic BS here - I am asking a legit question.

 

The days of static rear O2's signals are gone. Get that thinking out of your head. The PCM on most obd 2 vehicles utilize the rear o2 to trim. How could it possible use the rear o2 for fuel strategy if it switches slowly?The rear o2 is active in a myriad of ways. If you are a tech, use your scanner and watch the rear o2 activity of the next 10 cars in your bay. You will see a lot of activity. It has become the norm. But you have to interpret the theory and operation of each individual manufacturers criteria in order to effectively diagnose a cat code. Realistically, you have to trust the PCM after verifiying that all other outside influences are null. To date, the only manufacture that I am aware of the utilizes "the rear O2 sensor observation" for cat effiecency is Ford. and that is only on some Ford models. No sarcasm , only the facts, from a 15 year drivabilty/ master tech.

 

duly noted sir!

 

OK, I didn't do anything to this car until recently. As mentioned, I changed the fwd bank, pre and post cat O2 sensors, trying to avoid the cat. I put Auto Zone $8 platinum plugs in and then took the car to the dealer to verify it was the fwd CAT, they said Yes it was, I got a new CAT from somewhere else, installed it, reset the check engine light, then took off for a drive, I put 70 miles on it, stopped for something and when I got back in and restarted, the damn check engine light was on! I came home and pulled the codes, they were mis fire codes for #1-4. My buddy says that the non dealer plugs could be the problem. I cleared the codes and will drive it around for a while and see what happens.. Would these platinum plugs cause these codes, after about 200 miles?? Car is driving me nuts.....
Gary G.

 

Could be. Are they the correct plugs? If you're worried just buy some Honda plugs and see if it solves the problem.

 

The Auto Zone plugs were listed as a replacement, the dealer wants $15 a plug.......
Gary G.

 

Lets. See what the "master tech" says this time lol

 

buy ngk plugs. none of that bosch crap.

 

Generally you get what you pay for when it comes to stock replacement parts. In my experience thinking with your wallet only costs you money in the long run. That said I'm sure you can beat the dealer price on those plugs if you search for them on the internet (at RockAuto e.g.)

You could always buy one NGK replacement plug and see if it solves your misfire in that cylinder.