hi,customer just called me,carpet i cleaned on Wednesday is stinking,thing is i cleaned this carpet two years ago for different tenant that was living there at the time and the same thing happened,actually my last call back. Its a polypropylene,first time i put it down to bad ventilation,obviously not.Then i re cleaned it a left dryers.I have to do the same again.Im thinking its the carpet backing.Its oldish carpet .Any ideas .