Sorry, but I disagree. I have worked on many systems and this is a frequent problem.....If the check engine light is coming on then get it properly diagnosed. Do not mess with the A/C system yourself. Sorry Shiner, but telling someone to just add oil to the system is a horrible suggestion. Get the system vacuumed out and then properly refilled with the proper amount of oil and refrigerant by someone that is certified to work on A/C.