Toyota Repair: Check engine light, mud dauber nest, charcoal canister

Question
Terry,
I have a 02 camry 4cyl.I stoped to gas up and couldn't get the gas in. Took 5 min. to get 5 gals. the pump would cut off. The gas would come out like the tank was full. What ever that problem is turned on the check engine light. Is there a check valve that could be bad?
Thanks for any help  

Answer
If you don't mind laying on the ground, driverside rear wheel, look up under the car, find the charcoal canister, looking at it you will see a 3/4 soft hose coming out and going into the frame, ease it out of the frame and take a pair of pliers or screw driver and get that old mud dauber nest out, they love this hose, it's the vent hose for filling, pliers just mash along the hose, this is my method,I see others use the driver. if you really won't to make sure its clean remove the hose and dont crack that 800.00 canister, maybe more where you live.  if you find the dauber nest to be in the hose, even thou Toyota says you can't clear the code by disconnecting the battery (neg) terminal,I have and it has cleared them just some won't,  turn key on to crank turn key back off befor connecting battery or you could fry the ECU,leave off for 10 min or more. If it comes back on or no dauber nest you have a tank check valve stuck.  If I find a TSB on the check valve I will let you know, but hopefully it's the dauber.