No CEL. Something is rattling under the hood when the engine runs. I want to start it up and let it run so I can inspect it and find the cause. I'm thinking Ford must have allowed for a maintance mode to idle the engine in park, but I don't see anything in the owners book.
I'd do what Noobz suggested first. However if the cat. covertor heat shield is the cause, take it to the dealer if it has under 80K miles - it should be covered by 8/80 federal emissions warranty.
If you can't find the rattle by banging on the exhaust some preferably with a rubber mallet there is a method to keep the engine running that may help you find the noise.
This is the procedure, carry out the following sequence EXACTLY to activate the engine running diagnostic mode:
• apply the parking brake
• place the gear selector in the PARK position
• ignition in the OFF position
NOTICE: Do not start the engine.
• ignition in the ON position with the engine OFF
• within 5 seconds of the ignition in the ON position, fully apply the accelerator pedal and hold for
10 seconds
• within 5 seconds release the accelerator pedal, shift the gear selector to the DRIVE position and
fully apply the accelerator pedal
• hold the accelerator pedal fully applied for 10 seconds
• release the accelerator pedal and shift the gear selector to the PARK position
If the sequence is correctly executed the powertrain malfunction indicator (wrench) flashes once
per second when the gear selector is shifted to the PARK position. The engine may be then started by
cycling the ignition to the START position as you would normally do to start the car.
The PCM exits the engine running diagnostic mode when the gear
selector is shifted to any gear other than PARK, when the ignition is turned to the OFF or ACC
position, or the powertrain or hybrid-electric system voltage exceeds calibrated limits.