I have noticed that many of the PCM traces I analyze for people is that under I/M 240 tests that their Evap system is not passing the test, including mine.

In thinkiing about this and how evap is plugged into the intake I had a thought that maybe the little valve that sits next to left valve cover was dirty.

It took 5 minutes to take the valve off, then using low airpressure I had air blown through the valve and then that snakie looking plastic hose that connects to the valve and goes all the way back to cannister by right muffler.

Evap has always failed I/M test since I have owned the Rebel and after the cleaning I checked with Ease scanner and low and behold evap is now in a completed / passed state.

GM service manual talks about service cleaning, they state to use low pressure using some gas ( not air) based product but using my air compressor I set it to about 2 PSI and was fine.