Car in park idles fine, when driving seems ok. notice engine run a litttle rough when slowing down to stop. The car only has 84000 kilometers.when stopped idle drops below 500 rpm. not always . when it does act up it engine runs rough. I have taken car then out of gear and back into gear and the engine idles back close to normal but with engine slightly running rough. I have noticed that my gas milage has dropped slightly as well.

Check for trouble codes. You can get this done free at most car part stores.

Sometimes that's caused by a vacuum leak near the manifold area.

Sometimes air in the coolant will cause an idle problem. Air will keep the air temp sensor from sending proper info.
Hope this helps.

You are driving too fast.

try your ful injecton you mite have a injector clogged up try seafome it mite work cant hert to try

Here are the most common causes of idle surge, rough idle esp when cold, other symptoms include stalls at stops, slow idle speed, erratic idle speed, rough idle and engine hesitation (and other problems), it is in most cases the idle speed control air-bypass valve and or throttle valve and upper intake, these area's get full of gunk and combustion residue over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake

Sounds like the Torque Converter Lock-up Solenoid is failing. It will cause the car to run rough at slow speeds, and sometimes stall while idling in gear (at a stop sign for example)
To test this, locate the 2 or 3 wire connector on the left side of the transmission (looking at it from the left side of the car, it can be hard to find some times) Disconnect it. If the car runs and drives ok with it unplugged, the Lock Up Solenoid has gone bad. The solenoid itself is inside the valve body, inside the transmission (above the transmission pan)

First of all there is a vacume leak, second how is the air filter?, tell the husband to change the MAF mass air flow sensor and I would also change the TEMP tempreature sensor.

Possible Idle air control, simple to change on the throttle body

Here are the common cause of surges, cold stalls, stalls at stops, slow idle speed, erratic idle speed, rough idle and engine hesitation (and other problems), it is in most cases the idle speed control air-bypass valve and or throttle valve and upper intake, these area's get full of gunk and combustion residue over the miles and cause idle issues (stalls, low idle) like yours.
To correct this problem I want you to get a can of intake cleaner (ABOUT $5.00) from any local auto parts store like NAPA or Carquest, do not use carburetor spray, intake cleaner only or u will damage the Teflon coating inside the throttle valve and air bypass valve, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.

there are 2 things that usually cause this, one is a dirty intake idle control valve and the other is hard engine mounts, I would say that both most likely apply to your car. try cleaning the intake with the following procedure from Ford.
Here is the most common cause of surges and stalls and low idle rough idle, it is the idle speed control air-bypass valve and throttle valve (IAC for short), they get full of gunk over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.