So we're set to leave town on a much-needed weeklong jaunt tomorrow morning and my wife's car, the one we'd planned on taking, had to slog through some water during a thunderstorm this afternoon. 10 minutes after that, she's having trouble accelerating at low RPMs, the check engine and battery light come on, and after pulling over onto a side street and slowing, the engine cuts off. She didn't immediately restart it, but waited 20 minutes, it started fine, but during the rest of the drive home, she could feel the engine struggling as she slowed down and accelerated from low speeds. 4 hours later, it's still doing this. The battery is about 3 years old, and unfortunately her car doesn't have a voltmeter on the dash, so I don't know if the battery is suddenly having trouble putting out juice or her alternator is wacky or god knows what because fuck if I know anything about car electrical systems. I checked to see if the air filter was damp and the top of it was dry. I wasn't sure if there was any point in pulling that out to check further. We can always take my van, but I hate to take the hit on mileage over her compact car. If there's some idea of what this could be and any way I could fix it before tomorrow morning that'd be peachy keen.