EPA caught VW cheating - how does the car know it's being tested?

Only with half of what you say. They will do t he same on the emissions test, and continue to pass unless something is broken.

But yes, that means they'll get lower mileage, not just during the test.

VW should pay them for the extra gas they will have to buy, and pay them for the time it takes to go to the gas station and get it.

Maryland used OBD on cars new enough. That includes my 2000 car, but I don't think included my 1995 car.

(For the 1995 it used the dynamometer and tailpipe stick) I think when I turn 70, if I don't drive too much, I won't have to be tested. Or my car.

Sorry, I should have mentioned that the position I set out is that under English law and other jurisdictions will no doubt differ.

Depends on the state. In CT, the car only needs to pass the test for the year the car's VIN indicates, assuming they test old cars (CT doesn't on cars earlier than 1990).

You said it yourself. You can't pass emissions with pending codes. They have to run a scan to check this. That's why before they even stick the exhaust gas analyzer into the tail pipe they read the codes. No point proceeding with the test if there are unset codes, though if you're paying for the test they will complete it to check for other failure modes as well.

At least that's the procedure for the four vehicles I have had smogged every two years for the past 20 or so years. Also the procedure at the repair shop my relative operated until he sold it last month, and he probably did 3000 or so smog checks per year.

I guess you could claim that it is not a requirement to run a scan, it's just a requirement that you can't pass with pending codes and the only way to check for pending codes is to do a scan. If there is another way to check for pending codes other than doing a scan you would be correct, but I don't think that there is.

How did they check for pending codes if they did not use a code scanner? You can't pass with more than two pending codes (one on some years).

That shop would be shut down by the state if it was found that they were passing cars without checking for pending codes.

That was the big problem in California. A significant number of out-of-compliance vehicles were causing most of the pollution. Even though percentage-wise the number of such vehicles was small, in absolute numbers it was large enough to cause a problem.

The "catalytic converter test pipe" was popular for a while. But as you said, in most cases, all the tampering with emissions controls did not have any effect on mileage and/or power.

They look for the light on the dashboard that indicates codes have been logged.

In some places they always use the scanner to make sure, for instance, that the ECU wasn't reset immdiately before taking the car in for inspection. In some places they do not.

--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

."I'd like to know how the EPA found out about this hack "

Good question. I can understand how an individual could, for example "how c ome my car runs like shit right after testing" and this happening to everyo ne who owns that model. Then it gets around on the internet, the rest is hi story. Reverse engineering by watchdogs, or possibly reverse engineering ef forts by a rival car company.

But there is another issue. You know EGR does not turn a sportscar into a P into necessarily. Long time ago we used to plug up the PCV on cars because "It is losing vacuum with that thing". Yeah, not enough to even notice, and plus PCV makes your oil last longer. It also eliminates the crankcase smel l.

The EGR system actually makes cheap gas burn better. The system basically r educes the O2 content of the mixture which slows down the burning. this is what the additives in premium gas do. This allows for higher compression ra tios and more advanced ignition timing.

With premium (higher octane) gasoline you actually get a little bit more po wer. In the old days we could set up our cars for premium, and you tell you r olady "Don't put regular in my car !". Now the engine is tuned to the gas dynamically. The ECM literally advances the timing until the knock sensor reports a knock, and it is right there, you never hear it. With cheaper gas it will retard the timing.

If you disconnect the EGR in an engine on a modern ECM it will sense a knoc k and retard the timing to the point where you are not getting much of a bo st - if any. However on the manufacturing level you can change the program in the ECM to tolerate more knock, especially at 2,500 RPMs and heavy load full throttle. If that is the engine condition right now, WolksVagon can be pretty sure the driver it not going to object to a little ignition "ping".

The old days were great. We went to the car lot, said "Gimme the keys to th at Olds over there" and they did not aask for a license or anything, you to ok it for a ride with the dealer plate and put it on the freeway and see ho w passing gear works, see i it peels rubber, see if it overheats. Then you find out whether it has brakes or not.

Now, you get a carfax on it, look up the previous owner on the county regis ter to see how many times they have been sued or arrested, have someone run the codes to make sure it hasn't been reset. Use a DOT approved tread dept h gauge... Sickening.

They used to sell cars touting their performance, now they tout the interne t access and cupholders. and some of them run Windows with the touch screen . Look Man, I want a spedometer, oil pressure, engine temperature and amps or voltage gauges. Matter of fact, keep your damn radio, I'll go to Crutchf ield. Fuck all that.

But you simply cannot buy that, you have to buy what they got.

Caveat emptor.

Why people would not remove the "bypoass boxes" to return the vehicle to stock before submitting for E-Test is beyond me - - - . Same with "power tuners". They have the capability of storing more than one tune

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Officially, all cars 1996 and newer must be OBD2 compliant, but most jurisdictions using OBD2 for E-Testing only start at 1997 models because some 1996 models were not fully compliant. Only a very few

1995 vehicles had OBD2 capability as 1995 was "pre-standard"

Wow, even I wasn't aware of that. I was aware that actually a car can be ma de to run better without a cat, to the point where the emissions would be a bout the same, that something has to keep that cat lit, but not why they di d that. I thought it was just like a servo hunting and or some reason they couldn't get rid of it. But i have been out of the loop for some years now.

The bottom line is the only way to test a cat is by O2 content. They cnnot check by emissions because in a properly running car, and I mean REALLY pro perly, there are no emissions to convert.

The cat does not help cars the really run right, it helps cars with cumulat ive inaccuracies in the build. Normal production tolerances do not have to be as tight. Hell, they don't even lap the valves in anymore. That'll save you a few manhours on something with 32 valves eh ?

I still maintain that no regulation has passed without the approval of the automakers. They have lobbyists. The regs give them an excuse for highway r obbery. Literally. It also makes starting a new car company much harder, th us keeping down competition. No more Tuckers !

There's a word I haven't heard in a long time.

In ontario the testers are directly connected to a central computer and it is virtually impossible to go from stem 1 to step 3 without completing step 2 first.

A number of years back, some crooks were running a "good" vehicle through the test 5 or 6 times, entering the Vin for one that would not pass. They made changes to the system that prevented that pretty quick.

Didn't have any significant positive effect on mileage and or power.

And the "test pipe" stopped being an option in 1996 with OBD2 testing pre and post cat O2 - unless you bought an O2 fake-out device that generated a fake O2 signal (actually, 2 signals ----)- which caused other problems (genrally a lot poorer fuel mileage and not much power improvement, if any)

Except "pending"codes don't turn on the CEL, and the CEL does not indicate if monitors have been "set"

That.

You have a good point. I need to recheck my facts.

The software code allows all of the car's emissions systems to work when the cars are taken in for clean-air testing. But as soon as the emissions tests are complete, the system reverts to spewing pollutants. The cars emitted nitrogen oxide at a level of up to 40 times the standard level, the EPA alleges.