I've been getting an emissions code for the evap system and discovered that the last repair on the fuel valve was not sufficient to hold pressure and so need to replace the fuel valve in the front of the tank. I ordered the valve listed for the model and found that the 99 GMC Jimmy 4 door has a non-replaceable valve in a tank that is not available. All results that I can find are for metal tank models and 2 door. Mine is a plastic tank and 4 door. Anybody know where I can order a replacement tank?