What's up with the annoying pinging coming from my tailpipe?

[bhicks]

When I first purchased my Explorer I noticed a pinging/ticking noise coming from the tail pipe after I turned the vehicle off. It pings about 1-2 times per second at first then slowly decreases in sound and amount as the vehicle cools down. I had a Jeep a few years ago that did this same thing but much worse. I ended up having to swap out the cat converter. Is this pinging/ticking noise coming from the tail pipe usual for this year? My previous 2 Explorers never made this sound. Any help would be greatly appreciated.

 

[Dan Whitaker]

Metal expands as it heats and shrinks as it cools down. I'm betting it is the shields around your converters making the noise.

 

[rileyrs]

not a big deal, its simple physics happening.

 

[bill32399]

Those catilytic converters get pretty hot too.