Q: I have a 2013 Hyundai Elantra with 84,624 miles. The dealer recently replaced the engine under warranty. When I picked up the completed car, the check engine light came on within a couple of miles. I took it back, and they found a vacuum leak trouble code and needed to get a smoke tester to find the leak. They told me the problem was a contaminated “evap” canister. I am wondering if the smoke test could have contaminated the system or if that was even the problem.
— K.K., Chicago