08 Yukon Drive Sequence for Evap Readiness After P0442 Code Clear???

[KATfishing]

08 Yukon Denali 6.2 L AWD, 113K. One week ago I replaced my gas cap with a new OE gas cap after receiving a P0442 Evap small leak code. I cleared the code and have driven every day, mix of city and hwy totaling 400 miles so far. I just checked status of monitors and all says "ready" except for the Evap monitor. There are no codes pending. I am wondering a couple of things: 1) Will the Evap monitoring have to occur in order for a pending code, or could that have happened by now without the Evap monitor doing its test? 2) I know it's some sort of weird sequence and combination of conditions when driving for the Evap monitor to activate and do its test for readiness, but can anyone share those specific steps for my vehicle in order for this to happen? Ironically, I don't live in an area where I'm required to test for emissions. I just really want to know if I've fixed the problem by replacing the gas cap. There was NO problem filling the gas tank, so I'm not suspicious of an obvious vent problem, but I also know beyond a gas cap that it may be a bit of a pain to track down the problem. Thanks!

 

[Kraig]

http://www.obdii.com/drivecycle.html

 

[KATfishing]

Thank you!

 

[1_8TTony]

The evap monitor ALWAYS takes the longest time to set. In some cases, it takes so long that the state I live in (California), doesn't require the EVAP monitor to be "ready" for emissions testing purposes.

If you're wondering about whether or not the code is on it's way to coming back, you can use an OBD scanner and look at the "Pending Codes". This will inform you the status of any codes that may occur.

 

[KATfishing]

The evap monitor ALWAYS takes the longest time to set. In some cases, it takes so long that the state I live in (California), doesn't require the EVAP monitor to be "ready" for emissions testing purposes.

If you're wondering about whether or not the code is on it's way to coming back, you can use an OBD scanner and look at the "Pending Codes". This will inform you the status of any codes that may occur.

This is EXACTLY what I was wondering... if pending codes would show prior to EVAP monitor being "ready." After a week of driving I checked it yesterday and NO CODES but it was still saying "Not Ready" for EVAP. I then took a nice 45 mile hwy ride and this morning scanned it again and EVAP monitor now says "ready" and also NO CODES. I am relieved that a new gas cap took care of it this time. I had replaced the purge valve a few months ago from a P0496 code, so I was relieved today of feeling some resolution. Doesn't get much easier than a new gas cap, and I made sure it was OE -- $18 Amazon Prime! Yay

 

[KATfishing]

Just a quick follow-up on this thread. Soon after my last post about the gas cap fix, light came on again with codes for large leak and vent valve. I purchased the updated vent valve assembly and harness adaptor and installed it. All monitors except for Evap read "Ready" within a few drive cycles. After 3 weeks, FINALLY my Evap monitor reads "READY" and code reader says NO CODES. Does this mean it already tested the system for leaks/malfunctions and all is good with no pending codes, or does this just mean it is now ready to test and perhaps hasn't yet? There are no pending codes at this time. Trying to figure out when I can ring the bell!