Runs some TECHRON through it to cleam off the intake valves real good, change the oil, change the air filter, change the spark plugs, Make a 20 mile run at >100MPH to clean off the cats, drive HOT to th inspectionstation. If that doesn't work, adjust the fuel mixture a tad leaner. Next actio is to replace the catalysts (these are oxidation only--not 3 way I think)