Hi guys been a while since I been here, just wanted to know if any of you had a problem passing smog, I have a 1991 300CE that failed and was classified as Gross polluter. I Live in California. Have any of you had this issue. Just need to know where to start. The print out said just about every thing passed on the test but it fail at:

HC (PPM)
MEAS=908

CO (%)
MEAS=4.67

Result
GP Fail

Just looking at info as to where to start, thank you so much and any info will be appreciated.