I have a 99 F150 4.6 liter automatic 100k miles. The idling seems too high (No rpm gauge). When driving on highway and I let go off the gas pedal, it doesn't slow down as fast as the other cars I have. Is this normal?

Thanks in advance,

 

have you checked the throttle cable that might be your problem it might be stickin a lil bit

 

Can you put your odometer in test mode and check rpm's?

http://www.mustangworld.com/ourpics/fcar/dtcodes.htm

 

Thanks for the info. I'll check it this weekend.