Is this on your 88 lude? If that's the case then it shouldnt cause that. Try cleaning your O2 sensor with some hot soapy water or carb/brake parts cleaner. I have an O2 simulator build guide, but I'm not sure if it's gonna work on OBD 0 or pre-OBD systems.
here:
http://www.hstuners.com/forums/showt...threadid=17011