JessamynOct 28

My car is "It's ok that the check engine light is on, you can still pass state inspection" years old.

However, "the computer" won't pass it. My mechanic thinks it's because my car was built in Oct. and is 15 and 362 days old. Cars must be "over 15" to pass w/ a check engine light on (just an EVAP code, not a safety issue).

I think some programmer made the computer look for a number that was 16 or over in the "car age" slot. Got a new appointment on Monday. Wish me luck! #ComputersWereAMistake

Show threadberserk du soleil
@jessamyn in this scenario in the past . . . my check engine was on bc of the o2 sensor, and my mechanic told me he could reset the computer or something so that the light itself would turn off for, hopefully, long enough to go do the inspection. so, in case that sort of idea might help you too, depending on what your check engine light is about.
Oct 28 at 5:50pmWeb
Show threadJessamynOct 28
@aetataureate Thank you. My mechanic and the car inspector are the same person and he's as baffled as I am. Basically if it still won't pass someone at the state will have to go into "the computer" and pass it anyhow. I hope.
Show threadberserk du soleilOct 28
@jessamyn yeah i hope it all works out!! you need the equivalent of YOURSELF who has like "car inspection drop-in hours" haha. good luck!!
Show threadGemma SeymourOct 28
@jessamyn @aetataureate The usual cause of an EVAP code is that the seal on your gas filler cap is no longer working, and you just need to replace the gas cap.
Show threadGemma SeymourOct 28
@aetataureate @jessamyn This is not true, for the most part. There is a flag in the engine control unit specifically for the purposes of emissions testing. When you clear the codes, the car has to go through a process of observing the emissions sensors for long enough to trip the bit that tells the emissions testing computer that everything is operating and you didn't clear the codes just to pass the emissions test.
Show threadGemma SeymourOct 28

@aetataureate @jessamyn There are ways to "trick" the ECU into resetting that bit as soon as possible, and if you are lucky, you can make it to the testing station and through the test before the ECU decides to throw a code again, but it's an iffy thing, and the exact procedure varies from model to model.

The computer actually looks for patterns in your driving in an attempt to prevent you from fooling it.

Show threadGemma SeymourOct 28

@aetataureate @jessamyn In any case, in order to do this, you have to have a code reader hooked up to the car, so that you can see exactly when the bit flips to the ready state, and then *immediately* have the car tested.

An O2 sensor is usually a cheap part, but replacing it is often a huge PITA job, because of where the O2 sensors are usually located, and there are usually two of them in modern cars, one upstream of the catalyst and one downstream.

Show threadGemma SeymourOct 28

@aetataureate @jessamyn This article explains it pretty well. I have managed to get a car through the inspection process in NJ with a bad O2 sensor once, by doing the "drive cycle" with a code reader on board, but the repair still had to be done, later. In any case, that car wasn't 15+ years old.

https://repairpal.com/drive-cycle-emissions-readiness-monitors

Show threadJessamynOct 28

@gcvrsa @aetataureate Thanks so much for spelling this all out. But yes, just for those following along, in this particular case, we're not clearing the codes because they're for a thing that isn't required for me to pass inspection.

So my mechanic, who is also the guy at the inspection station, isn't sure *why* it wasn't passing, since it hits every mark it's supposed to hit because of its age (and yeah I did get a new gas cap which unfortunately didn't fix this)