i have been getting a gas odor for about the last month in my 97 blazer. I got one code p0440. The code came up when i was down to about 1/4 tank of gas but then cleared when i filled the blazer up.

I told my mechanic about this and he checked the vapor canister (behind the rear driver's wheel) and found it to be full of gas so he emptied it out.

I have also replaced the vent solenoid (the one about the spare tire) a year ago.

I ordered a new canister which will be here this week. I guess my question is, can a bad canister cause the gas smell? I really smell it when I fill up but there is no obvious leak anywhere (no puddles on ground). The smell is persistent no matter what amount of fuel i have in the tank.

So I guess I'm looking to see if the canister can cause this problem, and also is there a DIY somewhere showing or detail how to replace it.

 

The fuel tank is designed with a raised portion at the top to allow for expansion of the fuel. If you overfill the tank, when the fuel expands, it is pushed into the canister. The canister is designed to handle fuel vapor only. If/when raw fuel gets into the canister, it needs to be replaced, dumping it out does not fix it, the damage is done. When filling the tank at the gas station: when the nozzle shuts off, the tank is full, don't keep clicking it.

Fuel odor and P0440 might be caused by a rusted filler neck, or just from overfilling it. The EVAP monitor only runs when the fuel level is between 15% and 85%. That's probably why the light went out.... it'll come back on until the problem is repaired.

 

thanks for your response. I have had the neck replaced earlier this year, as well as the fuel level sending unit. I am guilty of "topping" off the tank from time to time when gas prices are lower. Hopefully the change of canisters will fix my issue, it should be here sometime this week.