I bought a 1998 Ford Mustang 3.6 brand new in 1998 . It has been taking care of , and then some. I gave it to my son a few weeks ago and it was running great as always before I left on a business trip. Now when I made it back home the check engine light is on and it idles rough. Now some times it does not do it , but when it does the check engine light goes on and it flashes and the A/C blows warm . Makes me want to think it s vacuum leak?
Thank you for writing in. The vehicle may be having issues with the idle air control valve. You can clean the IAC valve, or it may need to be replaced. You can also start by having the vehicle scanned for diagnostic codes at your local parts store or by a technician. A check engine light is a benefit and lets you know that a code has been set, which can help guide you if you know what the code is and what it stands for. Look into the check engine light and the IAC before you look for a vacuum leak. Good luck!