I have a 1998 Subaru Impreza and I just failed the NOx emissions test. Before the test I replaced the Catalytic Coverter and the O2 sensor, I replaced the air filter and changed the oil and filter.
My Hc was .3655 the Limit is 1.2
My CO was 7.1301 the limit is 15.00
My NOx was 2.4764 and the limit is 1.5
What do I do next? Eric