I've searched and searched, but haven't found a thread with symptoms quite like mine. I'd say around 50% of the time I start my Jeep, the idle goes up to around 2k and sits there. If I start driving it, it goes back to 7-800 by the time I'm out of the neighborhood, and stays there. I do have an exhaust leak at the manifold, but it isn't a bad one. I hooked it up to a diagnostic scanner as it was throwing a code (bad cat, assume it's from the exhaust leak). While hooked up to the computer, it idled at 2k for a minute or two, then 1100 for a minute, then settled in at 750. Throttle position showed 16* (too high I think?) at all idle speeds. Another thing...intake air temp showed 150ish with an ambient temp around 102...seemed high as well.
Is the exhaust leak the culprit for all this? I can't find any vacuum leaks, but haven't looked real hard either. Intake manifold maybe? I bought it with the leak and showing the same code and don't think it has become any worse over the last year or so, but the high idle is a new problem, just showing up a month ago. Aside from these issues, it runs great and has been very reliable. Thanks.