I have a 90 gt and it smells like it is running very rich. When I first start it up it runs great, after a few minutes the idle goes way up then drops way down to the point where it will stalls sometimes. I did just notice that the 02 sensor is broken and I dont know if that would cause the problem??? The motor is a 306 with gt40 upper and lower, 24 #er's, c/l76 meter,frpp t/b and a novi 1000. I just installed all of the parts. I did have the same problem before the build. Any help would be great.Thanks