My 99 Silhouette continues to fail emissions. Code P0440 EVAP control system. So far have replaced MAF sensor and had smoke test with nothing found. Next recommendation is Fuel pump assembly. Of note, dash gas gauge malfunctioning. Could really use some advice before I spend any more $.

Thanks,
Snog

 

The evap system can have failures in the gas cap, the fill hose, or anywhere between that and the charcoal canister (I can't remember if there is one on that vehicle, but I believe there is). It could also have to do with the sending unit in the tank if the seal is bad. You're just going to have to track it down. There should also be a dollar amount limitation so you won't go broke trying to fix the problem.