'95 V6, rough idle

[FULLSCALE]

My friend's '95 V6 Mustang idles rough, and he found a vacuum leak near the PCV valve. After fixing the leak, the idle is even worse!

Any common problems with these or suggestions on what to do next?

 

[MadStang]

Clean the IAC and MAF.

If that doesn't solve the problem, check the voltage to the coil pack, if it's getting power then you're fine, if not replace it. Replace the spark plugs & wires. The fuel filter may be bad. The fuel pump may be going bad. And those are usually the essentials of a rough idle.