I went for the DriveClean test and the car failed. At idle, all numbers were below the limits but at 25 mph, the NOx was 1500ppm when the acceptable limit is 505ppm. All other gases levels were well below the limits. Can this be an EGR problem or a cat problem. Two years ago I had the test done at the NOx levels were at 499ppm. Please help.
Mar 4, 2009 at 10:05 PM