Spitting on over run ?

Have noticed recently that occasionally on over run i can hear a spitting / popping type noise from under the car when on over run. Its a 1999 XEDi.

Hoping its just a hole in the exhaust or a bad seal on a join.

Any other suggestions ??

put a wet rag on yer rear end [egghaust that is] un wear a rubber glove [helf un safety] un wif ya doozle running push wet rag against hole ,un listen fer leaks if good should force rag away after it pressurizes, um if you have two hole rear bit ,jist use two rags un two hands ,snort. . . ..