try to do a fuel injector service and clean up the throttle body as clean as possible or carborator,get rid of that gum from a throttle plate,,coz thats the cause of the throttle plate stuck open (lean mixture) and so the sensor sense a bunch of air coming from the intake system and send a signal to the computer and then the computer command by using a gas to compensate the air fuel mixture,.,.,,.for idle only....youk now what theyre ryt,,try to elemenate this,,,under inflate tire pressure,wheel out of balance,overload,not shifting or change gear properly and most of all do the alignment,,dont just jump to the conclussion ryt away,dont do this advice "buy this and buy that"it wont help you out,,the best thing you do is to elemenate the things above one by one and you will feel the diference,.