I've had my car for a couple of years, and just suddenly it starts to idle funny, not always, only when I suddenly rev the rpms and then let it drop back down to idle it always seems like it wants to die.... any ideas

 

Maybe you want to scan the code to see if any sensors like TPS is faulty. You can connect the GND and TEN terminals in the diagnosis port underhood w/ a paper clip to do that.

It may also be a vac leak, possibly in the lower intake manifold. This is a common problem. Spraying carb cleaner around the turbo area and see if the RPM surges a little. If it does, you found the leak. If there is a leak and the idle isn't too bad, you may just want to leave it since changing the lower intake manifold will cost you 10+ hrs of labor that requires you to take the upper manifold and turbo apart - lots of work!

 

I agree that you should check your codes. Many of the codes are memorized in the comupter and will show up when you ground the ten connector.

I had an idle problem similar to yours and it ended up being a bad air temp sensor.