Stuttering after filling up

I have a 2014 Tacoma Prerunner 4.0 TSS, almost 200k. Recently, I filled the tank and later while passing someone had a stutter in the engine. Dealer said the tranny is slipping. It doesn’t feel like a transmission problem to me. Had it flushed and serviced. Ran great until I filled the tank and it did it again. I think it’s the charcoal canister because last summer I smelled gas in the cabin. No codes have been thrown. Any ideas or suggestions appreciated.

 

I would try testing the purge valve.. it should be normally closed I believe so if you remove it and blow through it both ways, it should not flow. An alternative would be the put a vacuum gauge on it with the valve unplugged and see if it pulls a vacuum. It should not when it's unplugged. Of course that will throw tons of codes