Ok so this is the 3rd time ive gotten my MIL light on 1-2 days after i fill up. 1st it said very minor leak and now its mass gross leak. Anyways i pulled it into my school and checked it out with the evap service machine. Pressurized the evap system and detects a leak duh (gas cap tighted) So we smoked the system. Smoke came out of the gas cap. So we thought it was a faulty cap and i took a cap of another scion tc the school owns. Didnt solve the problem. Took off the rubber boot thats around the filler, removed the wheel and the plastic cover. When we sealed the opening, the smoke was seen comming out of SOME PLASTIC cap that is on the filler tube.
Has anyone had any Evap leak problems? that involve the filler tube or gas cap? My tc is a 05 with 61k miles. No warranty i guess

 

MIL light...?
the CEL is the one that turns on with faults in the evap system/loose gas cap.

though i guess the mil is another name for it.. though it's not the same label for this particular car...

haven't sen any problems like this before... besides someone actually not tightening the cap on tight.

 

CEL or MIL is the same thing
Malfunction indicator light or Check engine light.
Toyota uses MIL in all its service bulletins

 

and uhh... the evap stuff is on the gas cap.

 

the gas filler has 3 tubes. One that lets gas in and 2 that i guess is evap. We smoked the system via the service port near the intake

 

Found problem!!!!! Vent valve doesnt fully close. It was leaking from the filler tube because thats a VENT, its suppose to vent but its no suppose to vent when the valve is closed. Need to replace whole Charcoal canister assembly, toyota doesnt sell just the valve.
http://scionbeat.com/Ownership/EG/EG041-06.pdf

Does anyone else have this problem?
BTW. When this problem first started i only had a code for small evap leak( cleared it) 3 weeks later mass gross leak + vent valve stuck open (cleared it) 2 weeks after that same codes plus 1 more. I saw the tsb and see that i need all 5 codes, so drove for few days with MIL on. Now i have all 5, so i went through the inspection at school