# I Pit SMOG TESTS! **URL:** \ **Category:** The BBQ Pit\ **Created:** [February 13, 2006, 10:36pm UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351 "2006-02-13T22:36:11Z")\ **Posts on this page:** 13\ **Page:** 2
**Author:** ![beergeek279](https://avatars.discourse-cdn.com/v4/letter/b/7ea924/32.png) [@beergeek279](https://boards.straightdope.com/u/beergeek279)\ **Post date:** [February 14, 2006, 7:14pm UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/21 "2006-02-14T19:14:20Z")
> [@duffer](#): > > Of course, PA is worse as you’re required to actually have a mechanical inspection. That must be convenient. Any other states do this? I think Texas but not sure. Ohh, it’s not too pleasant at all, to say the least…when I had my 93 S-10, it cost more to get it ready for inspection on a yearly basis than the vehicle was worth. Of course, there’s also emissions testing for people who live in counties around Pittsburgh or Philadelphia, but not the entire state, so some of the drivers have a 2nd sticker on their vehicle (I do, for example) and some of them don’t. They had talked about either phasing it out or spreading it to the whole state, but those poor mechanics spent so much money on the emissions testing that they have to be able to recoup their money. :rolleyes: ---
**Author:** ![Frank](https://avatars.discourse-cdn.com/v4/letter/f/3d9bf3/32.png) [@Frank](https://boards.straightdope.com/u/Frank)\ **Post date:** [February 14, 2006, 10:09pm UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/22 "2006-02-14T22:09:06Z")
> [@EnginNerd](#): > > Parts of Colorado do have emissions testing requirements. I think only Colorado Springs and Denver, however. Though, we’re supposedly phasing out emissions testing here in the Springs - thankfully, I might say. My last test, my car was something ridiculous like 1/1000 of the allowed level for one of the items. I knew that post was going to be confusing almost as soon as I posted it. The part you quoted was supposed to be referring to a physical inspection of the vehicle. I’ll try to be more clear next time. 🙂 We’re supposedly thinking about phasing out emissions up here too, probably to be replaced by the drive-by that others have referred to. One good thing about the drive-by is that it would also get the commuters from outside the zone who right now ignore the fact that they’re supposed to get tested. I could live with that. I could also live with extending the exempt period from five to ten years. ---
**Author:** ![VenusProbe](https://avatars.discourse-cdn.com/v4/letter/v/e495f1/32.png) [@VenusProbe](https://boards.straightdope.com/u/VenusProbe)\ **Post date:** [February 15, 2006, 4:25pm UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/23 "2006-02-15T16:25:41Z")
As the driver of a 40 year old Mustang, I personally think the emissions test is a good thing. Here in Washington state the car gets it’s first test on it’s sixth birthday and every two years after that. I took my 99 caravan through last December it took all of 15 minutes and 12 bucks. The Mustang is exempt being built prior to 1974, and it spews unburnt hydrocarbons and carbon monoxide. It runs as it was meant to when it was built. The big offenders are the clowns in their 10+ year old 4 bangers that they drive around with the check engine light on constantly and spewing the same amount of crap into the air. My car is actually cleaner than it was new because I burn unleaded and I put a much more efficient carburetor on it. I think we should have the mobile tests as well an fine the crap out of them. I also admit the state is making a freakin fortune off of them. ---
**Author:** ![RogueRacer](https://avatars.discourse-cdn.com/v4/letter/r/7ab992/32.png) [@RogueRacer](https://boards.straightdope.com/u/RogueRacer)\ **Post date:** [February 15, 2006, 6:50pm UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/24 "2006-02-15T18:50:04Z")
> [@duffer](#): > > I remember in Wisconsin we were required to do emissions testing every year. (Though they may have ended that, anyone know?) When was that? I’ve lived in WI for a good portion of my life and I never remember emissions testing. There certainly hasn’t been any in the last 15 years. I guess it could be a city or county thing around Madison or Milwaukee though? ---
**Author:** ![PunditLisa](https://avatars.discourse-cdn.com/v4/letter/p/4af34b/32.png) [@PunditLisa](https://boards.straightdope.com/u/PunditLisa)\ **Post date:** [February 15, 2006, 7:10pm UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/25 "2006-02-15T19:10:09Z")
Here in the Buckeye State, they may invest our tax dollars in illegal “rare coin” scams, but by God they finally got rid of the smog test. 😃 ---
**Author:** ![PunditLisa](https://avatars.discourse-cdn.com/v4/letter/p/4af34b/32.png) [@PunditLisa](https://boards.straightdope.com/u/PunditLisa)\ **Post date:** [February 15, 2006, 7:10pm UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/26 "2006-02-15T19:10:16Z")
Here in the Buckeye State, they may invest our tax dollars in illegal “rare coin” scams, but by God they finally got rid of the smog test. 😃 ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [February 16, 2006, 4:44am UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/27 "2006-02-16T04:44:52Z")
Former smog tech here. Cars do fail smog tests all the time. Trust me on this. Sometimes they fail for excessive emissions sometimes for other reasons. I have taken cars from way over the limit to clean as a whistle. I know that I have made a difference in the air we all have to breathe. FTR the State of California does not make a fortune on smog tests. They only get a small chunk of what a smog test costs $8-$12 IIRC. **Trunk** Your guy Stedman is as full of shit as a Christmas goose IMNSHO. > [@](#): > > dirty engines are highly variable and sometimes burn cleanly for short durations. So just how does the hot car owner predict that one of these magic clean times will occur when he is in for a smog test? > [@](#): > > arrive at the test site “hot”—having just come off hard driving on the freeway—which is a good way to make a dirty engine appear to be clean. So what’s his point? Converters and O2 sensors don’t work until they are hot. Is he advocating testing the cars cold? This would only increase the failure rate, and make his mobile testing idea look even weaker, since the smog tests would be catching more “failures” This guy is selling something, and doesn’t mind shoveling BS in order to make a sale. ---
**Author:** ![Clothahump](https://avatars.discourse-cdn.com/v4/letter/c/51bf81/32.png) [@Clothahump](https://boards.straightdope.com/u/Clothahump)\ **Post date:** [February 16, 2006, 3:47pm UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/28 "2006-02-16T15:47:38Z")
> [@duffer](#): > > Of course, PA is worse as you’re required to actually have a mechanical inspection. That must be convenient. Any other states do this? I think Texas but not sure. Not really. You get the smog test and a brake test, they flash your headlights, and that’s about it. The Texas state inspection sticker is just another road tax. ---
**Author:** ![Bookkeeper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bookkeeper/32/281_2.png) [@Bookkeeper](https://boards.straightdope.com/u/Bookkeeper)\ **Post date:** [February 16, 2006, 5:55pm UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/29 "2006-02-16T17:55:55Z")
In Ontario the PTB have just changed the regulations so that vehicles only need to be tested after 5 years instead of 3, and have removed the exemption for vehicles more then 20 years old, having apparently just realized that the older vehicles are spewing pollutants while the new ones have a 99% pass rate. in any case, the vehicle only has to meet the environmental requirements for the year it was manufactured, so anything antique/collectible is likely free and clear. The tests are every two years but they are planning to make it annual for vehicles over 12 years old. Other proposed changes will increase the $ limit for repairs from $450 to $600 (if the cost to repair the vehicle to non-polluting state is over the limit you get an exemption), and test by reading data off the car computer instead of running it on a test rig if the car is equipped for it. ---
**Author:** ![Trunk](https://avatars.discourse-cdn.com/v4/letter/t/87869e/32.png) [@Trunk](https://boards.straightdope.com/u/Trunk)\ **Post date:** [February 16, 2006, 6:32pm UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/30 "2006-02-16T18:32:45Z")
> [@Rick](#): > > I know that I have made a difference in the air we all have to breathe. No one is saying otherwise. You’ve caught the bad offenders. You’ve probably also needlessly tested 50,000 late model Toyota Corollas that didn’t come within a factor of a hundred of failing the smog tests. > [@Rick](#): > > So just how does the hot car owner predict that one of these magic clean times will occur when he is in for a smog test? They don’t. He’s just saying that the current method misses many of the bad polluters because the emissions levels are too variable. A good engine runs clean consistently. A bad engine sometimes runs clean. Sometimes runs poorly. The point is that testing every car on the road to capture a few bad apples is bad policy. > [@Rick](#): > > So what’s his point? Converters and O2 sensors don’t work until they are hot. Is he advocating testing the cars cold? No. The whole point of that section of the article is that we could nab the problematic polluters by setting up mobile testers on the roads where cars drive. This has the effect of NOT forcing every motorist to come in once a year for a test that virtually all new cars pass. Additionally, it doesn’t allow people to work the system by registering polluting cars in places without tests, or by fiddling with the engines before a test. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [February 17, 2006, 8:22am UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/31 "2006-02-17T08:22:09Z")
OK **Trunk** Let’s look closely at this guys claims > [@](#): > > Car enthusiasts—with high-powered, high-polluting sports cars—have been known to drop a clean engine into their car on the day they get it tested. So just how large is this problem really? In over 30 years of dicking around with cars on all levels I have never heard of anyone doing this. Unless someone can come up with a cite, I’m filling this in UL territory > [@](#): > > Others register their car in a faraway town without emissions testing This is a failure of the legislature, not of the smog inspection system. If the law makers say that if your car is registered in BFE instead of Denver you don’t have to get a smog check, then oh well. BTW this is a strawman. If you are exempt because your car is registered in BFE now it will be exempt under Stedman’s system unless the law is changed. > [@](#): > > or arrive at the test site “hot”—having just come off hard driving on the freeway—which is a good way to make a dirty engine appear to be clean. As I mentioned before, emission system are designed to operate hot. More straw since he intends to put his scanners on the side of the road, where the cars will be, um, hot. BTW, a quick blast down the freeway will not make a dirty car clean, but it will allow the car to run as clean as possible, since everything will be at operating temp. > [@](#): > > Still others randomly pass the test when they shouldn’t, because dirty engines are highly variable and sometimes burn cleanly for short durations. Well if the engine is worn and uses oil, that is not a sometimes thing. If you are discussing electrical failures, then we are dealing with yet even more straw. Yes electrical failures can come and go. But you have to keep in mind a couple of things here. First off if you claim that the fault can go away during the smog test, then you also have to admit that it can go away during the time that the car drives past the scanner. Yet there is one major difference here. Part of the smog test is verifying that the check engine light is off. An electrical failure that causes emissions to go up, will light a check engine light. If the failure goes away, the light remains. Since Stedman’s scanner does not read the check engine light, the advantage in the case of intermittent electrical failures goes to the smog check system. > [@](#): > > There is little evidence, Stedman says, that the city’s regime of inspections makes any difference in air quality. Scientific American did a study of LA air quality about 10 years ago. It confirmed what anyone who has lived here for more than 40 years could tell you, the air is way cleaner now then it was in the early 60’s. This did not come about because the clean air fairy visited. > [@](#): > > park them on freeway off-ramps around the city Now it is official this guy does not know what he is talking about. Look, here is the deal modern electronically controlled fuel injection system turn off the fuel to the engine during coast down. It does not take an automotive genius to understand that if no fuel is going into the engine, no emissions are coming out. So when you are slowing down on a freeway off ramp, what is the position of your throttle? Most likely closed. If your throttle is closed, and you are slowing down, the chances are excellent that the fuel to your engine has been cut off. > [@](#): > > The Speer Avenue sign is attached to one of Stedman’s devices…have a police car poised to pull over anyone who fails the test. I don’t know exactly where the Speer Ave. sign is, but let’s say for the sake of argument that you live ¼ mile away from there. You get in your car, start it and drive off past his scanner. Your O2 sensor is not yet working because it is cold; your converter is not yet working because it is cold, and you can has to have extra fuel because it is cold. You get a smog ticket even though everything on your car is working just the way it should, the problem is just your car is not yet warmed up. Nice revenue generation tool huh? Just how pleased are you going to be when you get your fifth one that week? > [@](#): > > for a test that more than ninety per cent of them don’t need I read that to mean that there is a 10% failure rate > [@](#): > > could test thirty thousand cars a day if these unit were in use 365 days a year that would be 10,950,000 cars tested. If they only were used 220 days per year you still test 6,600,000 cars. At a 10% failure rate you should see between 600,000 and a 1,000,000 cars that get their tailpipe cleaned up > [@](#): > > could identify and fix twenty-five thousand truly dirty vehicles Oh I have discovered the problem, he can’t do math. 25,000 is what about 0.2% of the cars tested? Not a very big number, if the current system is catching 10% Here are a few more problem with this system It does not inspect the evaporative system for leaks. Evap leaks put hydrocarbons straight into the air, without even going through the engine first. It does not do a functional test for EGR. EGR is a major reducer of NOX. EGR is only present at cruise. Under his testing scenario, NOX would not even be generated, so if could not be tested. No check of the check engine light, see my comments on intermittent problems above. No visual inspection. What if the pre-heat tube is missing? This has a large effect on cold emissions, but does not effect them warm. If it is missing your car will take longer to warm up, and as a result spew more crap into the air. If you don’t want to have your car tested every year, OBDIII might be of interest to you. Read the section near the bottom ["Beyond OBDII](http://www.aa1car.com/library/us796obd.htm) All I can say is, if after reading this, you still support Stedman’s idea then you had be careful about what you wish for, you just might get it. ---
**Author:** ![Necros](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/necros/32/11086_2.png) [@Necros](https://boards.straightdope.com/u/Necros)\ **Post date:** [February 17, 2006, 4:49pm UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/32 "2006-02-17T16:49:03Z")
> [@Rick](#): > > So just how large is this problem really? In over 30 years of dicking around with cars on all levels I have never heard of anyone doing this. Unless someone can come up with a cite, I’m filling this in UL territory Yeah, I’ve never heard of anyone doing this, either. Swapping in a new engine just for an emissions test would be crazy. BUT, people will make modifications to their cars for test day. I reinstall both cats on my car. I turn down the boost and limit the fuel via the engine management system. I know of others who will run a half alchohol/half gas mixture for the test. People are definitely willing to make SOME effort to avoid failing a test. Of course, now, I’ll probably roll into **Rick** ’s bay next time I go to get tested, and he’ll nail me. 😉 ---
**Author:** ![butler1850](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@butler1850](https://boards.straightdope.com/u/butler1850)\ **Post date:** [February 17, 2006, 8:51pm UTC](https://boards.straightdope.com/t/i-pit-smog-tests/344351/33 "2006-02-17T20:51:45Z")
> [@Frank](#): > > Colorado doesn’t do it; Massachusetts used to. (And maybe still does.) When I moved out here from Mass., I was amazed to see cars everyday that wouldn’t last 30 seconds back east. > . MA not only does the test every year (might be 2 years, I’ve escaped from that horrible state), but they do the test on a Dyno. The emmissions test is performed with the engine under load, rather than at an idle, like it used to be. There is, however, an exemption for AWD vehicles, as most garages don’t have a 4wheel dyno. NH does an inspection of all mechanical parts, suspension, brakes, exhaust, signals, lights, and horn, along with a computer diagnostic. Simply, the diagnostic looks for error codes in the ECU. If you’ve a CEL (Check engine light) lit, you fail. If you’ve emission related error codes, you fail. NH requires this state wide, instead of having to have actual emissions testing in the “higher pollution/traffic” areas of the southern part of the state. [Previous page](https://boards.straightdope.com/t/i-pit-smog-tests/344351.md?page=1)