It’s a 2012 Q5 with 75k miles. I was driving about 30mph, someone slammed on their brakes in front of me and I accelerated fast around them. About 30sec later engine light turned on, EPC turned on, then CEL started flashing and the car was shuddering hard. I pulled into a parking lot to look at the engine, the gas cap was extremely hard to remove while idling, strong gas smell and lots of smoke from exhaust, only started when pushing the pedal to the floor. Called AAA to get a tow (unfortunately they didn’t have an OBD scanner) and when I got home I realized one side of the hose had become disconnected. I plugged the hose back in to the PCV and replaced the diaphragm. I will be replacing the PCV and hoses with OEM parts but they had to be shipped, and I need the car for a very important work trip on Sunday. It started up immediately, EPC and CEL still on, normal suction on oil cap, but still shuddering while driving very noticeable while idling and still lots of smoke from the exhaust (not a continuous stream of smoke, more like a “sputtering”, like “puff puff puff puff”)

TLDR: CEL and flashing EPC came on after hard acceleration, extreme suction on oil cap and shuddering hard while idling, white smoke from exhaust, strong unburnt fuel smell, but no tea kettle or whistling sound. Oil level also normal. Noticed PCV hose was unplugged, put it back in and also replaced diaphragm. Engine sounds normal, normal suction on oil cap, started up right away but CEL and EPC still on and still shuddering/puffing white smoke from exhaust (not as hard as before). 

2012 Audi Q5 still having problems after PCV issue fixed