The evaporative emissions test is a non-continuous test because it only runs for a brief period shortly after start up. It is not continuously being monitored.
I did the same thing bcohen2010 described. The evaporative emissions tests only occur under specific conditions that allow it to detect a leak. So if the tank is kept above 3/4 full, it will not run and eventually trigger the check engine light which causes more headaches in the process. Clear all the codes, keep your tank full and drive enough to get all the other monitors set to ready. Then you will have no check engine light and only one monitor that registers as not ready.
I simply had the website queued up on my phone and showed it to the guy when he started complaining about it.
Thanks for the info. I guess it’s kind of a toss-up on my part, since I don’t know for sure if I have a problem, or if it was just that I didn’t tighten the gas cap enough (since it happened right after I filled up with gas). So, on the one hand, just driving normally and letting the tank get low might just reset all monitors and pass the test. But, on the other hand, it might be a persistent problem and it would be better to not do that. Hmmm.
One thing I just thought of: since this happened after I filled up with gas (either the same day or the next day), but my tank was still full or near full (I don’t drive very much), then how did it trigger the code if the test is only run when the tank is less than 3/4 full? The tank didn’t go down until after I got the code and I started driving around to try and clear it. Any ideas?
I wonder if they ever make mistakes, tow a car that shouldn’t be towed? Plate scanner could error & produce wrong plate number; active registration data-base could say plate number is not registered, when it actually is, data entry error etc. If car is towed that shouldn’t be towed, is the tow company fined, and also ordered to financially compensate the car’s owner for the inconvenience? IMO the plate reader technology remains untested, and is far from being ready for prime time.
None of my cars are OBD II, so I don’t have personal experience with readiness monitors. My OBD I car has to be emissions tested, exhaust gas monitored while being driven on a treadmill. OBD II cars are tested simply by examining the car’s emission-computer data. I don’t think the emissions testing place is looking for diagnostic codes; instead they are looking at the emissions-computer readiness monitor data. Likely somewhat correlated with the diagnostic codes, but not the same thing. So you can fail an emissions test with absolutely no diagnostic codes. Or you can – conceivably – pass an emissions test while having diagnostic codes.
As far as whether a scan tool can tell you if the readiness monitor data would pass or fail, yes, if it has the functionality required (not all do), and if the scanner’s user knows how to properly interpret the data. Unfortunately emissions testing procedures are very difficult to understand for someone who doesn’t do that job all the time. Sort of like if you go to France for a year, by the end of the year you’ll be able to understand most French conversations there. But if you then come back to the USA, by the end of that year you’ll probably no longer be able to understand French conversations. Use it or loose it I guess.
Remember that state and local gov’ts use your desire (or need) to drive your car to boss you around. So not much chance they will make the requirements necessary to drive your car easy to understand. Did the state make it absolutely unambiguous and clear what a “non-continuous” monitor is, when you researched it on a presumably Texas-state-owned website? I don’t think so … at least now you know why.
I see the answers here have covered any questions that were asked. The monitors being in ready status and no codes is an automatic yes. The car is ready for inspection. The monitors will have checked the operation of the different systems in order to be ready.
I had that code once and it went away and never came back. That’s why I was eager to comment.
Perhaps you had exceeded the threshold for triggering the MIL (it normally takes a few failed tests to trigger the MIL) so that the very next drive cycle it displayed the error even though your tank was now full. About the only scenario I can envision given the situation you described.
Honestly, I don’t know how it works. I just know they come through once a month with a plate scanner. I don’t know if they first notify the manager and get permission to tow. Or perhaps put a red sticker on the car first (I’ve seen those red stickers on cars sometimes.) Or perhaps only tow if it’s out of registration more than 30 days. Etc. Does seem a bit draconian to just tow vehicles that are newly out of the registration.
The purpose of course is to keep people from parking abandoned or non-running cars in the parking lot, since space is limited.
If it gets towards the end of the month and my situation isn’t resolved, I’ll go and talk to the manager and see what the deal is. Seems that there should be a way to be reasonable.
I assume these OBD I cars are old? Isn’t there a point where a car reaches a certain age and you don’t have to have emissions testing done anymore? Like 25 years or something.
I totally did not understand that. LOL Could you try again? Thanks!
They know the tests are done when the code reader indicates that the individual monitor is on ready status and not one second before. If your tank stays below a certain percentage of full for a few days you can bet that the evap. code is gone. The monitors probably have a good record of getting to ready status after the drive cycle is done but we only hear about the ones that don’t.
You didn’t have other codes so you will probably be one of the lucky ones.
OBD I-II transition occurred in the 1995/1996 timeframe. My OBD I car is 1992 model year. Yes, some states allow cars w/model year before a certain date to bypass emissions testing. In Calif that date is 1974 timeframe. My other vehicle, a 50 year old Ford truck meets that requirement, so it doesn’t require any emissions testing. That cutoff date is made by state politicians. Common sense says the cutoff should be the age of the vehicle, so date changes year by year, not a set in stone date. But common sense in politics? I don’t see that happening any time soon … lol …
As far as I know you can take the emissions test as many times as you like. Some emissions testing stations in Calif advertise that the second test is free, if the first one fails.
The inspector is not looking for anything, it is an automated test. The computer checks your vehicle’s PCM data; Monitors for pass/ready and current faults detected.
History faults are not considered, if the fuel cap was loose once 6 months ago, this will not cause a failed report.
No, I wasn’t asking if you could take the emissions test again. I was asking if you (George) could try again (to explain what you were saying to me), since I said I totally did not understand what you were saying. Specifically, this part:
So you can fail an emissions test with absolutely no diagnostic codes. Or you can – conceivably – pass an emissions test while having diagnostic codes.
How could you pass an emissions test while having diagnostic codes?
The OBD II emissions test requires a certain set of the computer’s readiness monitors be complete. Which set that is varies by location. Neither of my vehicles uses OBD II, so I don’t know the answer to your question, but it is a good question. I’d guess that in most cases if there’s a diagnostic code active, that would prevent at least one readiness monitor from being in the complete state. Whether that would cause an emissions test fail, varies by location.
I wonder if there are any current & active OBD II codes that don’t also turn on the CEL? My Corolla (OBD I) has a code for faulty switch in the AC system. I don’t think if that switch failed it would affect emissions, but might still turn on CEL. Don’t know, b/c my particular Corolla doesn’t have the AC option.
