High idle Hydrocarbons

[PorscheLover@aol.com]

hello folks,

    I have a little problem smogging my ' 87 5KS Quattro. At idle (750 RPM) 
the hydrocarbons were 965 with 120 being the max. However at 2500 RPM it 
drops down to 56 with  140 being the max. Everything else passes but that one 
reading puts it in the gross polluter category. Is this an indicator of a bad 
O2 sensor? Any help would be appreciated and please mail responses directly 
to me at PorscheLover@aol.com.

Thanks,
Rob Hill