If you're troubleshooting engine problems, air is simple — and probably not the problem. Your vehicle gets its air through the cold air collector box, or air cleaner. Unless the air filter inside it is totally clogged, your engine should be getting enough air to keep it going.
In a worst-case scenario, something has gone amiss with your engine control unit (ECU), and it’s keeping air from mixing properly with the fuel. If that’s the case, a “Check Engine” light should be glowing on your dashboard and the best you can do is call a tow truck and get to a repair shop.
But the problem is most likely something else: One of the vacuum hoses may have become disconnected, or your PCV valve may be malfunctioning, either of which could keep your car from breathing properly. To troubleshoot the problem, do the following to check the hoses and the PCV valve:
Look at all the hoses under the hood. Have any of them become disconnected or broken? Do you hear air whistling while the engine idles — if it can? One strategic lost hose can slow or stop your engine. If this is the case, reclamp the wanderer or tape the hole and you’ll soon be on your way. Of course, if you make a habit of checking and replacing worn hoses before disaster strikes, you can avoid this trouble completely.
Check your PCV valve to make sure that it’s clear and functioning. And here are instructions for checking, cleaning and even replacing a PCV (positive crankcase ventilation) valve.