Over a week ago my ’16 was scheduled for state inspection. Wouldn’t you know it, the day before the inspection, a transient ODBII code popped up. I know what it is, nothing serious but it turned the Check Engine light on and they can’t pass a car like that. I have a code reader so I reset the error but then all the emissions test status’ get reset to ‘Not Ready’ until certain conditions are been met.

I followed procedures outlined in previous posts (Let the car idle for 5 minutes then steady 55 MPH speed for 5 miles, then coast down to 20 MPH without touching controls (that part is impossible with an M7). Then repeat that procedure. All the emissions tests went to ready status except Evaporative System.

To clear the Evaporative System test, another post suggested letting the car sit unused for at least 17 hours then drive it. The post said it could take as many as 7 cycles like that to clear the test. I’ve tried that 7 times now for over a week but the Evaporative System test is still not ready.

Does anyone know how I can get this cleared? This is really frustrating and time consuming especially knowing that there has never been anything wrong with the car’s emissions controls. There must be a simple way to clear this so I can get the car inspected. Thanks in advance!

 

On some scan tools you can force it to run the evap test but not using just ob2 scanner it has to have the function to do it! would need a bi directional scanner to do it, but not all them will do it! the other problem is the temp outside the car will not run the test unless the temp is above a pre-set temp

 

Meet the following conditions and the test will run -

Barometric pressure > 70 kPa
Fuel level between 10 - 90%
Coolant temp and intake air temp within 14F
Start drive cycle
Coolant temp greater than 145F
Engine run time before shutoff > 10 min
Drive distance before engine shutoff > 5 miles
Ambient air temp at end of drive cycle between 32 and 93 F
Stop drive cycle
Wait 40 minutes
Two test attempts allowed per day

 

also GM cars and trucks are the worst to run the evap test! i have seen it take a few days or longer, also again the outside temp comes into play

 

For next time, don't clear the code. Just let the check engine light go out on its own.

 

Are these the qualifications for the C7, or the general GM qualifications for OBD2 vehicles? I'm trying to get my 2000 GMC Sierra 2500 through emissions and the evap test is one that takes forever. Of course, it didn't help with a screwed up fuel level sensor that either read full or empty and swapped readings at random times throughout a tankful of gas. I've got that fixed now but still stuck on that test too.

 

That's right out of the 2016 Corvette Service Manual.

 

I don't know what state you are in, but you can probably pass the inspection right now. Most states will allow 1 not ready and still pass. My wrx is the same. That evop test is still not ready after 500 miles but I still pass with it not ready.

 

Good point! In New York state you are allowed one "Not Ready" monitor.

 

Thank you so much for that information! I stopped by the inspection station this AM and they confirmed that they can pass a car with one emissions system Not Ready. Inspection is scheduled for 8:30 tomorrow AM.

Thanks to everyone who commented!

 

Also pending codes don't count either. I had a bad O2 sensor rear its ugly head just before I was going to get a vehicle smogged. It still passed as the check engine light wasn't on yet.

 

Recently CA has added the pending code as a fail.

 

Because of course they did. Wonderful.