Here is the situation. 2001 model, 4.3. I have no codes, either current or stored, related to the the Evap system, even though I have the charcoal canister removed and the three hoses hanging free, and the electric connection on the purge valve is unplugged. The problem is you can't put gas in the vehicle except at a painfully slow rate. The vent valve above the spare tire is new. If you pull the vent hose, coming from the gas tank, off of the charcoal canister, you can fill the tank at the normal rate. I determined that the canister is bad. NOW, the evap system doesn't work properly anyway and I'm not getting any codes. So, I'm thinking of just removing the charcoal canister and splicing the gas tank vent hose directly to the hose that goes to the vent valve, then plugging off the small line that goes to the purge valve, and calling it good. I'm wondering about excessive gas fumes if I remove the charcoal canister????? I could put a new canister on for about $100, but the system isn't working anyway and I wonder how long before the new canister would plug up from fumes and cause problems. I don't have to worry about emissions testing. Hoping some of others here have dealt with this and have been successful in safely "modifying" the system.

 

We don't discuss disconnecting or modifying emissions equipment here on the Blazer Forum. You are also not passing the emissions readiness test and it will eventually set a code and turn on the SES light. Just replace the canister. I did on my 2004 Avalanche for exactly the same problem - incredibly slow fuel fill, and it has a 30 gallon tank. Be careful with those hoses and the seals - they need to seal well to pass the various tests that the PCM does on a regular basis. The key to keeping this from happening again is to not overfill the tank. When it clicks off at the pump - hang it up - you're done.

 

Sorry I broke the rules.

 

No biggie! I'm sure you have correctly diagnosed the problem as your charcoal canister. Why do you feel that your EVAP system wouldn't work if you replaced it?