Lower then usual idle with some vibration

Is it when you first start the car up? If so its cause the engine isn't warmed up yet mine in cold weather idles at 1k till it starts to warm then goes down to about 800 rpm while sitting. If I don't let my car warm up a little and drive it while in warm weather it shakes a little at stop lights but then once warms up its fine. I don't think there's a way to adjust the idle that I know of. Oh and mine is a 2000 with a 2.7. You could also do basic maintenance and make sure all your fluids are filled, your oil is in good shape, spark plugs, also check your battery if its the original from when car was made might be time to change it so the car gets better power to all the electronics in car. Could always throw in some fuel injector cleaner like one that says full fuel system cleaner good to do every 3 to 5000 miles. Then again I run premium in mine all the time but there can still be carbon build up. Well let me know what happens, I don't think its anything bad :D

Well.. It did this with a warm-hot engine.. New gas tank and it seems to be fine.. Just changed an oxygen sensor and got a high voltage code from O2 sensor any ideas on that? Also what's the easiest way to check the sparkplugs? Thanks alot :) I'm thinking new battery when I got the money.. Prolly an optima yellowtop if possible.. :S

Well the spark plugs are easy to take out just take the screws off the top of the coil then pull it out and you need the spark plug socket along with an extension to loosen the plug and maybe if you have something thats telescoping and a magnet on end you can get them out easy, if the plug is black then there no good, if there some what white then thats good, but easy way to tell if there bad is you'll start to get really bad gas mileage or lose power when you step on gas. I have a set of Bosch Platinum with 4 contacts no need for gapping :D but they was like 7 a plug. I also have a K&N air filter was thinking of cold air intake but its 260 bucks and thats a waste. But I do notice my car has better acceleration with the k&n filter

thanks alot for the response.. i found out after new gas its fine!... im guessing really crappy gas :( .. also did you just change the filter to K&N or the whole intake? thanks alot ! :D

Just the filter was like $45 for filter and maybe you had some water in your gas maybe should try different gas station i usually goto Sunoco and get premium so keep engine clean although i might get better mpg if i used regular lol

alrighty.. i'll need a new airfilter anyways!.. also as for premium and reg.. i noticed premium gave a bit better gas milage, response on throttle was the same on both types of gas.... when the car is floored.. well.. premium doesnt do much.. unless you care about 2MPH faster.!.. lolz.. but that also has to with with other errors and such.. so basically premium gave me a bit better gas milage and thats all.. might keep the engine lasting longer but who knows? all i can say is the premium doesnt pay for itself unless it does help your engine last longer and cleaner.. otherwise.. premium turned out almost useless for highways.. city.. i notice same.. slightly better gas mileage. i forgot to state.. i can be slightly lighter on the gas with premium.. so it does show a bit with the pedal but not much :)