420 420 420

[1 Lucky Texan]

no i'm damm proud of are canadian school sestem they use my intire generation as a experement to teach kidds to spell useing phonics gess that dident work as well as they planed. my ecu time is very limited so i rush alot when on here. but thiss is just a small part of my world of fixing subarus

 

 

yeah, that psycholinguistics cr@p went thru some of our State school systems back when I was a kid. When I'd come home, my mom would have to re-teach me the real way to learn reading/pronunciation.

 

but, maybe, you could just hit the spacebar at the end of a thought once in while?

 

 

;^)

[Fairtax4me]

 

Sorry, couldn't resist!

[J A Blazer]

Eats shoots and leaves. Eats, shoots and leaves. Eats shoots, and leaves. Punctuation makes all the difference.

[J A Blazer]

Question: What is Subaru's 'official' position under the following circumstances, which describe my present situation: Upstream O2 sensor new; all heat shields in place; no exhaust leaks; car passes state-mandated emissions test. Yet still throws the occasional 420. I refuse to throw more money at this problem. Does Subaru acknowledge the propriety of an anti-fouler, which as I understand it would reduce the frequency of such codes? TIA.

Edited October 1, 2012 by J A Blazer
clarify

[1 Lucky Texan]

I doubt SUBARU can have any position that violates Fed or State Laws. Wouldn't use of any device to alter the function of the emissions systems on newer cars be outlawed in many places?

[J A Blazer]

My understanding is that the anti-fouler does not 'alter' the function of the emissions system; it merely reducess the frequency of these 'spurious' codes. The triggering of a 420 code does not result in any adjustment of the fuel-air mixture, ignition timing, etc.; it merely signals that some arbitrary efficiency 'threshhold' is not being met, and that 'threshhold' apparently exceeds federal emissions standards. Am I wrong?

[1 Lucky Texan]

My understanding is that the anti-fouler does not 'alter' the function of the emissions system; it merely reducess the frequency of these 'spurious' codes. The triggering of a 420 code does not result in any adjustment of the fuel-air mixture, ignition timing, etc.; it merely signals that some arbitrary efficiency 'threshhold' is not being met, and that 'threshhold' apparently exceeds federal emissions standards. Am I wrong?

 

Oh, I understand the issue - just saying, it is unlikely Subaru, as a corporation, could endorse it.

 

Plus, the cat could actually be bad, or you could have an exhaust leak.

 

what you could 'get away with' is different than what is 'required'.

[J A Blazer]

But if the car passes emissions tests how can the cat be 'bad?'

[Fairtax4me]

Subaru is more likely to recommend a reflash of the ECU tan to use an anti-fouler. Anti-foulers are NOT intended for use on oxygen sensors, and ARE illegal in areas that require emissions testing because they alter the way the ECU reads exhaust gas content.

[J A Blazer]

If I have to pay for a reflash of my ECU, what is the dealer likely to charge?

[brus brother]

My understanding is that the anti-fouler does not 'alter' the function of the emissions system; it merely reducess the frequency of these 'spurious' codes. The triggering of a 420 code does not result in any adjustment of the fuel-air mixture, ignition timing, etc.; it merely signals that some arbitrary efficiency 'threshhold' is not being met, and that 'threshhold' apparently exceeds federal emissions standards. Am I wrong?

Well, I am inclined to agree with you about these "spurious" codes. I clear the cel every now and again if it hasn't gone off in the meantime to make sure no other code has come up other than 0420.

I can clear the code and have all systems ready to pass emissions. For the rest of the time I have 2 small pieces of black masking tape that cover the cel and the blinking cruise light.

I hope the tape doesn't violate the no tampering laws.

[1 Lucky Texan]

But if the car passes emissions tests how can the cat be 'bad?'

 

where I live, the definition of failing for most gas cars built after 96 is, first, the CEL is on. Additional examination involves, making certain the fuel filler neck isn't modified, making certain all/most of the monitors are 'complete, probably other stuff.

 

Again, you asked Subaru's position on the anti-fouler. Certainly i can't speak for them and I may be wrong, perhaps you could email them and ask.

 

 

There ARE ways to handle 'nuisance' codes by re-flashing the ECU. Supposedly, and individual is allowed to do it for off-road use only. Dunno about a dealership. Again, what you, a dealership or some 3rd party can get away with, is different than the law.

 

I personally know someone who reflashed their ECU to kill off about 14 codes related to a failed secondary Air Injection system. That person even has an 06 WRX wagon like mine. But. it is only legal for an offroad vehicle as I understand it. It isn't illegal, yet, to use the tactrix cable, Romraider software and ECUflash to actually DO it.

[J A Blazer]

In Virginia there is an actual 'snif' test in which they put a probe in the exhaust and measure something.

[1 Lucky Texan]

In Virginia there is an actual 'snif' test in which they put a probe in the exhaust and measure something.

 

they only do that here on older cars - plus, I think pre-96 AWD may be exempt due to lack of 4WD dynos. They used to measure at 1200-1500 rpm IIRC. What's required in Montana might be a lot different than California. There could be some States that don't care about a CEL if the car passes the sniff test. I dunno.

[ivans imports]

We have no air care of any kind here at all there is on the coast but not in the interior. I realy duobt i could even find a shop with a working exhaust gas analizer. It whould show a lean condition if you did put one on it. when i pull the plugs on the ?able cars they are white and way to clean 0 deposits. My buggy did thiss untill i put in the 550 injectors. And sudenly it had coulor to the plugs nice tan deposits and came into stioch [sorry that one i cant spell] . Anyway the injectors are just to small to feed sutch a big piston engine. thiss is also why the 2.2 dosent set the 420 code has the same size injectors but smaller pistons. I converted my top feed rails to side feed rails to get more feul to engine. whould not work on air asist injectors but worked good on the 251. One other thing is very overlooked is the comprestion of the engine if low on any holes will not make as mutch vacume witch will not pull hard enuff on map or mas and cerate lean conditions.

[1 Lucky Texan]

I'm in NO position to offer a critique, I'll leave that to the real mechanics, but cardoc on 'another' forum has tried to put together a post and a video to hlep folks with 420 problems.

 

fyi

 

 

http://www.subaruoutback.org/forums/66-problems-maintenance/49537-p0420-diag.html

[idosubaru]

But if the car passes emissions tests how can the cat be 'bad?'

This is what I don't like. Much about this doesn't make sense. A catalytic converter that passes an emissions test is not worth a $1,000 replacement repair....$1,000 to replace a converter that's converting...and not polluting? weird.

 

Catalytic converters are being replaced by the truck load for thousands of dollars a day due to P0420.

 

Someone should add up all the gasoline, electric, warehousing, and coal needed to mine, smelt, manufacturer, ship, store, recycle and supply the huge market of catalytic converter replacements caused by the P0420 code...for converters that by-and-large ***pass*** emissions testing. LMAO . A pollutions monitoring device that causes massive, unnecessary pollution? Brilliant!

 

Converters are not failing the emissions sniff tests in Maryland....even when they throw a P0420 code they'll pass the sniff tests.

 

I don't trust the converter replacement frequency and diagnosis being liberally handed out.

[ivans imports]

it gets better shops are stealing the factory subaru catts and replacing them with cheap chinese ones or none at all had 3 customers that had no idea there catts had been stolen. One they just riped out the o2 wireing and told them it whould be normal to have the check engine light on. Had a strait pipe and they had charged her hundreds of $ for stealing the catts. they probly got 200$ for the used catts as scrap.

[Frank B]

All those good cats getting replaced are because those so-called mechanics don't know what they're doing, and they're looking for easy money from people that don't know any better. In this day and age it's not hard to look up information online, it would take less than a minute for someone that doesn't know a thing about cars to find out that 0420 doesn't mean that they need a new cat. It is a waste Gary, I agree 100%.

 

I think it has something to do with the air/fuel mixture and/or the catalytic converter temps. I think that, because the only time 0420 comes up on my 96 legacy is when I'm driving like a granny, or stuck behind one! I'm not a reckless driver but I'm no slouch either. I think when people drive easy, it causes the condition that will throw this code. I'm sure that you all have noticed that subarus like the higher rpm. The gear ratios are lower so the engine rpm is higher in any given gear compared to most other cars. I think when people drive easy, or the auto transmissions shift up too soon for fuel economy, it causes the lean mix/cold cat condition, and throws the code. Maybe ask your customers to keep it out of overdrive/5th gear unless they're on the interstate and see if it changes things. They may even notice an increse in fuel economy too...

[bratman18]

That's actually amusing because Subaru cats aren't really worth that much for scrap compared to other vehicle makes. And it's unfortunate that you have to worry about thieves everywhere you go.

[Fairtax4me]

The Cat temp theory could be proven with an EGT sensor in the cat. Put it in a car that doesn't and has never had an issue with the 420 code (like mine) and compare that with readings from a car that has recurring code 420. Put an AFR sensor in it too to see if the low temp readings coincide with lean mixture readings.

 

Ill be a tester! Who wants to fund it!? :-P

[ivans imports]

update the 03 test forester after 3 months of periumiun feul the 420 whent away came in for broken o2 wire but no more 420 the good gas fixed the problem but took at least 20000kms. And the scrap guys give me a 100$ each for used subaru catts the aftermarket ones they give me 5$. anyway have been beating up on peoples check engine lights all last week fixed two that had light on for 6 years or better one broken wire at rear by canister. And one broken wire above the gas tank having many problems with the emision wireing at rear of car.