Well, I must admit I have not many clues about this issue. Louis' reign was so short and unimportant that it is skipped by most Historians and he is rarely counted as a "true" king of Spain at all.
The main butterflies... well, Philip V would not recover the throne in the first place. That means that the king in charge isn't an hypocondric oldman dominated by his wife, but... would Louis' ministers be different? If they are the same that his father's ones, there would be little or no differences. If not, well, I don't know what would be changed.
A thing that actually could go differently would be the Spanish policies in Italy after the War of Polish Succession. Philip V, deeply influenced by his second wife Elizabeth Farnese, gave the reconquered Kingdom of Naples to his son Charles, who was son of Elizabeth and half-brother of Louis and the would be Ferdinand VI. The relation between Elizabeth and Ferdinand was hellish cold and I suppose that that power-hungry woman wouldn't be in terms anyting better with Louis. However, this time Philip V isn't the king anymore, but just an old depressed nobleman whithout power. Louis could kick Elizabeth and her sons out of the court if he is too much annoyed of them, and claim the throne of Naples for himself. The problem is that:
a) Naples returning to the Spanish throne violates the Treaty of Utrecht. Austria is exhausted by the War of Polish Succession but Britain (who was neutral in that conflict) isn't. That would lead to a war between Spain and Britain. How would it go? I suppose that something like the War of Jenkins' Ear that erupted in 1739 in OTL under a way more stupid casus belli.
b) In a worse-case scenario for Louis, Elizabeth Farnese could visit her husband and use him to stage a coup against his son...
Another thing to consider is that the Spanish succession line could be altered, though it is not sure: Louis and his wife hated each other and didn't even talK to the other. If their relation doesn't go better in the following years the throne would still go to an older Ferdinand VI. But as Ferdinand didn't have issue despite he was in way better terms with his wife, maybe Louis could force the queen to do her job in some form, and make a heir in order to have Elizabeth and her sons out of the successon line. That would be a great change, because it would produce and 18th century whithout the reigns of Ferdinand VI, Charles III and Charles IV.