just did the 3rd set in as many weeks, right after a cold start spray some carb cleaner under the intake, if the idle changes it's time for a set of gaskets and while your at it a pcv plate. if your getting lotsa check engine codes and or a crappy idle it's a good chance it's leaking, i've been seeing 02 sensor 1 and 2, 02 sensor control 1 and 2, hot film airmass sensor and a few other codes i can't think of at the moment with these leaks