The dirty cost of one man's hypermiling?

[SentraSE-R]

Originally Posted by euromodder

You'd expect these to return to normal with normal driving, right ?

Yes.

Originally Posted by euromodder

Did you P&G all the way on such a long trip?

Yes.

Piwoslaw, yes, CARB requires the California metropolitan counties to do full emissions (sniffer) testing. 21 states and some rural CA counties only require CEL/MIL and OBDII drive cycle monitor readiness flag/data history checks.

Mech, I'm sorry I haven't responded earlier to your thoughtful posts. I will follow up on your mechanical efficiency suggestions in time. Efficiency isn't my focus right now. It's the ethical quandary of saving a little gasoline while increasing my hydrocarbon, NOx, and CO emissions manyfold. Instead of beating the EPA estimates by 76% while spewing out 10X, 20X, or other massive air pollution through an unlit cat, I can simply drive normally (albeit slowly), beat the EPA estimates by 40%, and have normal emissions that are also reduced by 40%.

[California98Civic]

Originally Posted by SentraSE-R

Efficiency isn't my focus right now. It's the ethical quandary of saving a little gasoline while increasing my hydrocarbon, NOx, and CO emissions manyfold. Instead of beating the EPA estimates by 76% while spewing out 10X, 20X, or other massive air pollution through an unlit cat, I can simply drive normally (albeit slowly), beat the EPA estimates by 40%, and have normal emissions that are also reduced by 40%.

That's all well and good, but you don't know yet if the CAT or related systems are working properly, regardless of how you drive. Getting into the ethical quandary seems still premature. Check the systems. Test. Don't guess, right?

[SentraSE-R]

I have little reason to think the cat, O2 sensors, & emissions systems aren't working properly. When I'm missing a chicken, and find a coyote in the chicken coop, I'd waste a lot of time looking for hawks, snakes, and raccoons to find the culprit.

[Piwoslaw]

How about a heating pad wrapped around the cat? It could take a few watts from the car's electrical system, which would slightly increase fuel consumption, but still less than normal driving or even idling, yet it would keep the cat hot (with some extra insulation). It could also be wired so that you could prewarm it block heater style, reducing the emissions from a cold start.

[dcb]

Originally Posted by SentraSE-R

I have little reason to think the cat, O2 sensors, & emissions systems aren't working properly. When I'm missing a chicken, and find a coyote in the chicken coop, I'd waste a lot of time looking for hawks, snakes, and raccoons to find the culprit.

Umm, your sample size is two tests on two different days under different conditions.

Since you disconnected the battery prior to the first test, or otherwise reset the ECU (the readiness monitors were not set for some reason), it was in a different place in its retraining (and not even a valid first test for comparison purposes).

HC does not appear to be the most stable thing to measure to begin with:
http://www.epa.gov/otaq/regs/ld-hwy/...v/ftp-us06.pdf

How do you know it wasn't a throttle position sensor issue? Or operator issue? You don't.

If you are worried about low speed emissions, then stop idling. Your high speed test was fine and well within normal variations. You can usually pay these same folks $20 or so to do a test ad hoc, need to eliminate the variables before losing sleep on this one.

There isn't even evidence of a coyote here, more like a sasquatch, or a yeti

Farnsworth: "Bunk! Bunk, I say! Bring me a bag of Bigfoot's droppings, or shut up!"
Ranger: "I have the droppings of someone who saw Bigfoot."
Farnsworth: "Shut up!"

[niky]

A heating pad isn't hot enough. You need the cat to be running at a few hundred degrees to work.

[SentraSE-R]

Piwoslaw, The cat lights @~500 degrees F. I was seeing cat temperatures of 1101-1185 degrees F on my 900 mile drive last week. If I wrapped a heating blanket around it, I'd set the blanket and my car on fire.

Originally Posted by dcb

Umm, your sample size is two tests on two different days under different conditions.

Since you disconnected the battery or otherwise reset the ECU (the readiness monitors were not set for some reason), it was in a different place in its retraining (and not even a valid first test for comparison purposes).

HC does not appear to be the most stable thing to measure to begin with:
http://www.epa.gov/otaq/regs/ld-hwy/...v/ftp-us06.pdf

How do you know it wasn't a throttle position sensor issue? Or operator issue? You don't. There isn't even evidence of a coyote here.

If you are worried about low speed emissions, then stop idling.

??? The two tests show consistently higher than average HC and NOx emissions from my car. The difference between the two tests was 100 miles driven with the cat lit. Otherwise, both tests were driven on the same roller smog test station by the same operator on the same low rpm/higher rpm driving "course."

The state of the drive cycle readiness monitor readiness flags only marks OBDII data logging status. It certainly has no effect on emissions control or testing. Snake 1.

How is the TPS relevant to emissions testing? What TPS issue should I suspect, and why? It's another snake you're looking at. What operator issue? I, the layman, should suspect the smog test operator of doing what?

[dcb]

Lol, you did disconnect the battery didn't you Had a code you were trying to remove maybe? Yeti 1 and 2, computer told you you had another issue and you swept it under the rug. You didn't disclose the battery disconnect, assuming you knew it had to be hypermiling. There is a snake here allright

The ECU learns, not just the monitors, but also short and long term fuel air trims and other software peculiarities. The shortness of being reset (battery disconnect) can easily explain the difference.

Testing procedures also indicate variance from test to test in HCs, see the link.

If the tps were somewhat oxidized from lack of use, it could give a different reading after being used a bit more, maybe the ECU didn't think it was quite at idle the first time. Maybe the operator moved the gas pedal differently the second test. Who knows, too many variables here, don't jump to conclusions without eliminating some variables.

The high speed test was comparable though, so don't think you are automatically polluting a lot more in any event.

You are looking at a henhouse in the middle of a zoo full of open cages and you don't realize it. It is much to early to be blaming hypermiling for your observed results.

[SentraSE-R]

Dcb, you haven't read the thread. I cleared the MIL 800 miles and 4 months before the smog tests. I explained my car's history with the multiple misfire TCs. The ECU should have learned all it needed to during those 800 miles. The only major change to my xB between the two smog tests was that I lit the cat for 100 miles.

I happen to have checked my xB's absolute and relative TPS recently to compare them with my wife's car. Idle TPS remains rock-steady at 11.8. Relative TPS is always 8 lower than absolute TPS.

[dcb]

Originally Posted by SentraSE-R

Dcb, you haven't read the thread. I cleared the MIL 800 miles and 4 months before the smog tests. I explained my car's history with the multiple misfire TCs. The ECU should have learned all it needed to during those 800 miles. The only major change to my xB between the two smog tests was that I lit the cat for 100 miles.

Originally Posted by SentraSE-R

??? The two tests show consistently higher than average HC and NOx emissions from my car. ...

http://ecomodder.com/forum/showthrea...ery-11445.html

by me you can pay the emission station $20 for an ad hoc test. There may be a better way to kill your engine that doesn't make the ECU go wonky too.

Originally Posted by SentraSE-R

The state of the drive cycle readiness monitor readiness flags only marks OBDII data logging status.

There is a huge assumption there, ECU software is made by humans whom can be unpredictable. If the monitor states are stored in the ECU they can be used by any program routine. I deal with invalid assumptions in software daily, I've seen different ECUs on cars do different things under the same circumstance precisely because they were developed independantly (i.e. 800+ mile drive cycle)

Originally Posted by SentraSE-R

I happen to have checked my xB's absolute and relative TPS recently to compare them with my wife's car. Idle TPS remains rock-steady at 11.8. Relative TPS is always 8 lower than absolute TPS.

Yes, after not being driven for a while. You said it was sitting a while before the first test and a short drive, not saying it is the problem, but not convinced you have identified the problem correctly with such a "testing" procedure. How do you know the codes are related to key off? and what other ways might there be to kill your engine without causing a CEL (there might not be, but there are on other cars, again it comes down to different people developing the code basically).
http://ecomodder.com/forum/showthrea...-how-4356.html


And you still have not addressed the impact of the high speed tests being essentially the same on both tests, how much time do you spend idling? If it is very little then you don't have to worry so much about the low speed reading, which was within specifications anyway.