I don't know if i have a problem or not. When I let off on the gas the car doesn't begin to slow down very quickly, very gradual. If i put it in neutral the idle seems ok, 750, This is a 4.0. I have noticed the tach go up in rpm a few times after i let off on the gas but it does come back down. Could this be a vacuum leak. I have been getting a cel for lean engine that i have been unable to correct for a while.

 

Manual or auto trans? The manual there is timing before engine braking really kicks in, like 5-7 seconds.. think it is mpg measure. With my GT and louder exhaust, you can hear it change while you feel it.

I have also noticed our cars roll very well when not in gear/braking/uphill

 

Auto trans

 

Hi drakefamily2,

Have you brought your Mustang to the dealer for diagnosis? They'll be able to determine why your check engine light is on and if the RPMs are normal. Let me know if I can help!

~Natasha

 

I had it at ford dealer for 3 days, they never could clear cel.

 

If they couldn't clear it in 3 days, they must not be very good.

 

Could be, they had the ford guys at detroit hooked up thru their laptop but no one could find anything. Ther best guess was alcohol in fuel which was not it. I've a long list of stuff thats been eliminated but still have cel. Car runs ok except for maybe slow decel and rpm jumps.