That little stutter when you step on the gas isn't going away on its own, and ignoring it just burns more expensive fuel. Spring is the best time to handle a professional high-pressure fuel injection cleaning before the summer heat hits and repair shops get backed up with road-trip prep.
A typical US shop visit runs about $250. We want to get that price down at the counter first, and then figure out how to spread out what is left so it doesn't hurt.
Remember that the 0% for 18 months on purchases and balance transfers from date of account opening is a hard deadline, not free money. If you still owe a balance when those 18 months run out, the card company will charge you interest on the original amount from day one.