Jeep troubleshooting free

have you checked plug gap as this makes any car miss if not correct also coil packs could be faulty

You should take the car into a dealership for inspection. A guess is that the heater core started leaking coolant and that has shorted out the blower motor.

it sure can among other things to drive u crazy.....(back feed into other things)

Its hard to tell, but first most part I would get a second option on what is going on with the motor. 99% of the time your gas cap will not cause the engine light to come on at all. I don't believe Jeep Liberty's even have a sensor to detect that. Don't drive it, a clak clak clak sound coming from the motor it self could be as simple as adjusting a few things or something more serious. Good luck and feel free to ask more questions for help.

does it have CEL if so dont neglect it take it to an auto zone or advanced auto parts they can check OBDII systems for free that should help pin point the problem.

Replace your catalytic converter. Check your exhaust manifold for leaks aswell

Just adjust the idle down.

3.1 AND 3.8 ARE KNOWN FOR UPPER AND LOWER INTAKE GASKETS

That is completely normal for your jeep product idol ranges it does this while warming up it should drop back to 800 when completely warm or when you put it in drive and everything is a go try using a better spark plug from AC DELCO lifetime warranty ones that'll keep some of the heat under control and abnormalities in your jeep product don't forget to change your timing belt at correct interval if not sure when that is call your local dealer and ask the service dept at how many miles should you bring in for timing belt change but of course you can change the belt your self with a little determination and knowledge.

It does sound like a vacuum leak. Get a can of WD-40 and start spraying around the carb. It will rev up, and U can pin point the loose vacuum hose, are crack vacuum hose.