'07 Santa Fe: Can replacing Evaporative Emissions canister/Purge Valve fix hesitation/stuttering?

Reading elsewhere seems to indicate that this part is related purely to clean emissions, and the engine will still run well if they fail...I just won't pass an emissions test. I'm about to shell out $900 to replace these parts (based on diagnostic code from shop), and I'm just not convinced this is the cause of the hesitations during acceleration that I'm experiencing. Second opinions?