Bullitt Mustang Backfire

Hello All,

I own a 2008 Bullitt Mustang. The past six months I have noticed a backfire. It only happens after the car has been driven and cools down for a few hours. It doesn’t happen after sitting all night. The car is under warranty and my dealer says it is normal. The car also runs better when it is cold. I would appreciate any help. Thanks…

Last time the spark plugs where changed?

Is it a noise out the exaust, or from under the hood?

mileage is 23,000, orignal spark plugs. I had one plug and plug wire changed by dealer because of misfire. The noise is out of the exhaust.

If it’s still under warranty, take it to another Ford dealer.

When, exactly does it happen? At idle? Accelerating? Coasting?

It happens the first deacceleration after starting the car.

Since it didn’t do it before, have another mechanic take a look. My GTI ‘popped’ on decelleration from day one.

You also might post this in a Mustang forum, probably folks there familliar with it.

You need to scan it for codes as a first step. Maybe there’s a problem in the air injection system.